{"gene":"FRMD7","run_date":"2026-04-28T17:46:04","timeline":{"discoveries":[{"year":2006,"finding":"FRMD7 was identified as a novel FERM domain-containing protein expressed in human embryonic brain and developing neural retina, with mutations causing X-linked idiopathic congenital nystagmus, suggesting a specific role in control of eye movement and gaze stability.","method":"Mutation screening, in situ hybridization, expression analysis","journal":"Nature genetics","confidence":"High","confidence_rationale":"Tier 2 — foundational discovery paper, 147 citations, multiple families with 22 mutations identified","pmids":["17013395"],"is_preprint":false},{"year":2009,"finding":"FRMD7 knockdown during retinoic acid-induced neuronal differentiation of Neuro-2A cells results in altered neurite development, demonstrating a functional role for FRMD7 in neuronal outgrowth and development.","method":"shRNA knockdown, in situ hybridization, immunohistochemistry, neurite morphometry","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 — clean KD with specific morphological phenotype, replicated across cell and tissue models","pmids":["19892780"],"is_preprint":false},{"year":2013,"finding":"FRMD7 directly interacts with the plasma membrane scaffolding protein CASK; CASK promotes FRMD7 co-localization at the plasma membrane where together they enhance neurite length. IIN-associated FRMD7 mutations impair CASK interaction and plasma membrane co-localization. C-terminal CASK mutations that cause nystagmus specifically disrupt CASK–FRMD7 interaction.","method":"Immunoprecipitation–mass spectrometry (IP-MS), co-immunoprecipitation, co-localization imaging, neurite outgrowth assay, domain-mapping of CASK mutations","journal":"Human molecular genetics","confidence":"High","confidence_rationale":"Tier 2 — reciprocal IP-MS plus functional co-localization and neurite assays, moderate evidence","pmids":["23406872"],"is_preprint":false},{"year":2015,"finding":"FRMD7 is specifically expressed in starburst amacrine cells of the retina. Loss of FRMD7 leads to selective loss of horizontal direction selectivity in retinal ganglion cells and a transition from asymmetric to symmetric inhibitory input to direction-selective ganglion cells, establishing FRMD7 as a key regulator of neuronal circuit asymmetry required for the horizontal optokinetic reflex.","method":"Frmd7 knockout mouse, immunohistochemistry, electrophysiology (patch-clamp), optokinetic reflex behavioral testing","journal":"Neuron","confidence":"High","confidence_rationale":"Tier 1–2 — KO mouse with defined cellular and circuit phenotype, multiple orthogonal methods, 116 citations","pmids":["26711119"],"is_preprint":false},{"year":2011,"finding":"The C-terminus of FRMD7 is essential for its cytoplasmic subcellular localization; a truncating mutation (c.1003C>T) causes nuclear mislocalization and loss of co-localization with F-actin, whereas missense mutations do not alter F-actin co-localization.","method":"EGFP-tagged constructs in Neuro-2A and HEK293T cells, confocal microscopy, rhodamine-phalloidin staining","journal":"Molecular vision","confidence":"Medium","confidence_rationale":"Tier 3 — single lab, localization with mutation functional link but no in vitro reconstitution","pmids":["21386928"],"is_preprint":false},{"year":2013,"finding":"An IIN-associated FRMD7 missense mutant (C271Y) accumulates in the nucleus rather than the cytoplasm, possibly due to disruption of a nuclear export sequence downstream of the FERM-adjacent domain; this mutant acts in a dominant-negative manner to inhibit neurite formation.","method":"Transfection of tagged mutant constructs, immunofluorescence localization, neurite outgrowth assay","journal":"Human molecular genetics","confidence":"Medium","confidence_rationale":"Tier 2 — localization with defined functional consequence (dominant-negative neurite inhibition), single lab","pmids":["23406872"],"is_preprint":false},{"year":2012,"finding":"Overexpression of FRMD7 in Neuro-2A cells promotes neurite outgrowth after retinoic acid-induced differentiation and upregulates mRNA expression of neuronal cytoskeletal genes including MAP2, NF-L, NF-M, and MAPT, suggesting involvement in cytoskeletal dynamics of both F-actin and microtubules/neurofilaments.","method":"Transfection of full-length FRMD7 in Neuro-2A cells, quantitative RT-PCR, rhodamine-phalloidin staining, confocal microscopy","journal":"Molecular vision","confidence":"Medium","confidence_rationale":"Tier 3 — single lab overexpression study with gene expression readouts, moderate follow-up","pmids":["22690121"],"is_preprint":false},{"year":2013,"finding":"A novel FRMD7 missense mutation (c.635T>C, p.L212P) reduces Rac1 GTPase signaling activation compared to wild-type FRMD7, as measured by GST-PAK2 affinity precipitation, implicating FRMD7 in Rac1-mediated neurite development.","method":"GST-PAK2 affinity precipitation, co-transfection of FRMD7 and Rac1 in HEK293T cells","journal":"Molecular vision","confidence":"Medium","confidence_rationale":"Tier 3 — single lab biochemical assay with functional readout, no reconstitution or structural validation","pmids":["23946638"],"is_preprint":false},{"year":2011,"finding":"Two FRMD7 isoforms (FRMD7-FL and the shorter splice variant FRMD7-S) co-localize and co-immunoprecipitate with each other in NT2 cells, and FRMD7-FL overexpression upregulates FRMD7-S expression and alters neurite development.","method":"Co-immunoprecipitation, immunofluorescence, RT-PCR, neurite morphometry in NT2 cells","journal":"Molecular vision","confidence":"Medium","confidence_rationale":"Tier 3 — single lab, co-IP plus neurite phenotype","pmids":["22128244"],"is_preprint":false},{"year":2019,"finding":"FRMD7 mutations in human fibroblast-reprogrammed neurons (iNs) reduce complexity of neuronal processes (total neurite length, number of terminals, maturation rate), and are accompanied by significantly increased expression of the three main Rho GTPases.","method":"Direct neuronal reprogramming from fibroblasts, immunofluorescence morphometry, RT-PCR for Rho GTPases","journal":"Brain and behavior","confidence":"Medium","confidence_rationale":"Tier 2 — human neuron model with defined morphological phenotype and signaling readout, single lab","pmids":["31743612"],"is_preprint":false},{"year":2020,"finding":"FRMD7 directly interacts with the loop between transmembrane domains 3 and 4 of GABRA2 (a GABA-A receptor subunit critical for receptor transport and localization). IIN-associated FRMD7 mutants (p.Ala194Thr, p.Arg325Gly) show decreased binding to GABRA2. In frm-3 (nematode FRMD7 homolog) null C. elegans, FRMD7 mutants fail to rescue locomotion defects and impair GABAAR fluorescence recovery after photobleaching.","method":"GST pull-down, co-immunoprecipitation, FRAP in C. elegans, locomotion rescue assay","journal":"Investigative ophthalmology & visual science","confidence":"High","confidence_rationale":"Tier 2 — reciprocal biochemical interaction plus in vivo genetic rescue with multiple orthogonal methods","pmids":["32446246"],"is_preprint":false},{"year":2019,"finding":"A novel FRMD7 missense mutation (p.K269Q) inhibits neurite formation and extension, and disrupts FRMD7 interaction with CASK, supporting a model in which FRMD7–CASK interaction is required for normal neurite outgrowth.","method":"Transfection, neurite outgrowth assay, co-immunoprecipitation","journal":"Acta biochimica et biophysica Sinica","confidence":"Medium","confidence_rationale":"Tier 3 — single lab, co-IP plus neurite phenotype","pmids":["30576400"],"is_preprint":false},{"year":2020,"finding":"Frmd7 knockout mice generated by EUCOMM/COMP repository confirm FRMD7 expression in the retina restricted to starburst amacrine cells and show a specific horizontal optokinetic reflex defect with unchanged gross retinal morphology and electrophysiology.","method":"Antibody and X-gal staining for expression, high-speed eye tracking, electroretinography, histology","journal":"Genes","confidence":"High","confidence_rationale":"Tier 2 — knockout mouse model with expression confirmation and behavioral/functional phenotyping, corroborates Neuron 2015 findings","pmids":["33007925"],"is_preprint":false},{"year":2024,"finding":"Two frameshift FRMD7 mutations produce truncated proteins that escape nonsense-mediated mRNA decay (NMD) but are degraded via the ubiquitin–proteasomal pathway, suggesting that loss-of-function through proteasomal degradation of truncated proteins is a pathogenic mechanism.","method":"Western blot, qPCR, plasmid expression of mutant constructs, proteasome inhibitor assays","journal":"BMC medical genomics","confidence":"Medium","confidence_rationale":"Tier 2 — biochemical demonstration of protein fate with pathway identification, single lab","pmids":["38279119"],"is_preprint":false}],"current_model":"FRMD7 is a FERM domain-containing protein expressed in starburst amacrine cells of the retina and in developing brain regions controlling eye movement; it promotes neurite outgrowth by modulating actin (F-actin), microtubule, and Rho GTPase (Rac1) cytoskeletal dynamics, acts at the plasma membrane in a complex with the scaffolding protein CASK, and interacts with the GABA-A receptor subunit GABRA2 to regulate inhibitory synapse localization—functions collectively required for establishing the asymmetric inhibitory circuit in direction-selective retinal ganglion cells that underlies the horizontal optokinetic reflex, and whose loss causes X-linked idiopathic infantile nystagmus."},"narrative":{"teleology":[{"year":2006,"claim":"Identification of FRMD7 as the causative gene for X-linked idiopathic infantile nystagmus established that a previously uncharacterized FERM-domain protein is required for gaze stability and eye-movement control.","evidence":"Mutation screening across multiple families (22 mutations), in situ hybridization showing expression in embryonic brain and developing retina","pmids":["17013395"],"confidence":"High","gaps":["Cellular function of FRMD7 unknown","Retinal cell-type specificity of expression unresolved","Mechanism linking FRMD7 loss to nystagmus not established"]},{"year":2009,"claim":"Demonstrating that FRMD7 knockdown impairs neurite development during neuronal differentiation established a functional role in neuronal morphogenesis rather than merely a genetic association with disease.","evidence":"shRNA knockdown in retinoic acid-differentiated Neuro-2A cells with neurite morphometry","pmids":["19892780"],"confidence":"High","gaps":["Molecular mechanism of neurite regulation unknown","Whether effect is cell-autonomous in retinal neurons not tested"]},{"year":2011,"claim":"Characterization of FRMD7 subcellular localization and splice variants revealed that the C-terminus is essential for cytoplasmic retention and F-actin co-localization, and that two isoforms (FL and S) physically interact, linking FRMD7 to cytoskeletal regulation.","evidence":"EGFP-tagged constructs with confocal microscopy and phalloidin staining; co-IP of isoforms in NT2 cells","pmids":["21386928","22128244"],"confidence":"Medium","gaps":["Direct actin-binding activity not demonstrated biochemically","Functional significance of isoform interaction unclear","Studies performed in non-retinal cell lines"]},{"year":2012,"claim":"FRMD7 overexpression upregulated cytoskeletal genes (MAP2, NF-L, NF-M, MAPT) and enhanced neurite outgrowth, broadening its role from actin to microtubule/neurofilament dynamics.","evidence":"Transfection in Neuro-2A cells with qRT-PCR and confocal microscopy","pmids":["22690121"],"confidence":"Medium","gaps":["Whether cytoskeletal gene regulation is direct or indirect unknown","No in vivo validation"]},{"year":2013,"claim":"Discovery of the FRMD7–CASK interaction and its requirement for plasma membrane localization and neurite extension provided the first defined molecular partnership, while identification of Rac1 GTPase modulation revealed a signaling mechanism for cytoskeletal regulation.","evidence":"IP-MS, reciprocal co-IP, domain mapping of disease mutations disrupting CASK binding; GST-PAK2 affinity precipitation for Rac1 activity","pmids":["23406872","23946638"],"confidence":"High","gaps":["Whether FRMD7 directly activates a Rac1 GEF or acts as a scaffold unknown","Structural basis of FRMD7–CASK interface unresolved"]},{"year":2015,"claim":"Frmd7 knockout mice revealed that FRMD7 is expressed exclusively in starburst amacrine cells and is required for asymmetric inhibitory wiring onto direction-selective ganglion cells, explaining how its loss selectively abolishes horizontal direction selectivity and the optokinetic reflex.","evidence":"Knockout mouse with patch-clamp electrophysiology, immunohistochemistry, and behavioral optokinetic testing","pmids":["26711119"],"confidence":"High","gaps":["Molecular mechanism by which FRMD7 specifies asymmetric wiring not identified","Whether FRMD7 acts pre- or post-synaptically in starburst amacrine cells unclear"]},{"year":2019,"claim":"Patient-derived reprogrammed neurons confirmed that FRMD7 mutations cell-autonomously reduce neurite complexity and dysregulate Rho GTPase expression, validating findings in a human neuronal context.","evidence":"Direct neuronal reprogramming from patient fibroblasts, morphometry, and qRT-PCR","pmids":["31743612"],"confidence":"Medium","gaps":["Rho GTPase upregulation may be compensatory rather than causal","Retinal-specific neuron subtypes not recapitulated in this model"]},{"year":2020,"claim":"Identification of a direct FRMD7–GABRA2 interaction linked FRMD7 to inhibitory synapse receptor trafficking, providing a molecular explanation for the loss of asymmetric GABAergic input seen in knockout mice.","evidence":"GST pull-down and co-IP for biochemical interaction; FRAP and locomotion rescue in C. elegans frm-3 mutants","pmids":["32446246"],"confidence":"High","gaps":["Whether FRMD7 regulates GABRA2 localization specifically in starburst amacrine cell dendrites not shown in mammalian retina","Relationship between CASK and GABRA2 binding (simultaneous or competitive) unknown"]},{"year":2024,"claim":"Demonstration that frameshift FRMD7 truncations escape NMD but undergo ubiquitin–proteasomal degradation clarified that loss-of-function through protein instability, rather than mRNA decay, is a common pathogenic mechanism.","evidence":"Western blot with proteasome inhibitor treatment and qPCR for mRNA levels","pmids":["38279119"],"confidence":"Medium","gaps":["Whether all IIN-causing truncations share this degradation fate not tested","Protein half-life in native retinal neurons unknown"]},{"year":null,"claim":"The structural basis of FRMD7's interactions with CASK and GABRA2, whether these interactions are simultaneous or mutually exclusive, and how FRMD7 molecularly instructs the asymmetric wiring of starburst amacrine cell dendrites remain unresolved.","evidence":"","pmids":[],"confidence":"High","gaps":["No crystal or cryo-EM structure of FRMD7 or its complexes","Whether FRMD7 functions as a GEF scaffold or direct Rac1 activator not determined","Mechanism linking FRMD7–GABRA2 interaction to directional asymmetry in mammalian retina not established"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0008092","term_label":"cytoskeletal protein binding","supporting_discovery_ids":[4,6]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[2,10]}],"localization":[{"term_id":"GO:0005886","term_label":"plasma membrane","supporting_discovery_ids":[2,4]},{"term_id":"GO:0005829","term_label":"cytosol","supporting_discovery_ids":[4,5]}],"pathway":[{"term_id":"R-HSA-1266738","term_label":"Developmental Biology","supporting_discovery_ids":[1,3]},{"term_id":"R-HSA-112316","term_label":"Neuronal System","supporting_discovery_ids":[3,10]},{"term_id":"R-HSA-162582","term_label":"Signal Transduction","supporting_discovery_ids":[7,9]}],"complexes":[],"partners":["CASK","GABRA2","RAC1"],"other_free_text":[]},"mechanistic_narrative":"FRMD7 is a FERM domain-containing protein that orchestrates the development and wiring of direction-selective retinal circuits underlying the horizontal optokinetic reflex. Expressed specifically in starburst amacrine cells, FRMD7 promotes neurite outgrowth by modulating actin and microtubule cytoskeletal dynamics through Rac1 GTPase signaling and interacts with the scaffolding protein CASK at the plasma membrane to support neurite extension [PMID:19892780, PMID:23406872, PMID:23946638]. FRMD7 also directly binds the GABA-A receptor subunit GABRA2, regulating inhibitory receptor localization and thereby establishing the asymmetric inhibitory input onto direction-selective ganglion cells required for horizontal direction selectivity [PMID:32446246, PMID:26711119]. Loss-of-function mutations in FRMD7 cause X-linked idiopathic infantile nystagmus by selectively abolishing horizontal direction selectivity in retinal ganglion cells [PMID:17013395, PMID:26711119]."},"prefetch_data":{"uniprot":{"accession":"Q6ZUT3","full_name":"FERM domain-containing protein 7","aliases":[],"length_aa":714,"mass_kda":81.6,"function":"Plays a role in neurite development, may be through the activation of the GTPase RAC1. Plays a role in the control of eye movement and gaze stability","subcellular_location":"Cell projection, neuron projection; Cell projection, growth cone","url":"https://www.uniprot.org/uniprotkb/Q6ZUT3/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/FRMD7","classification":"Not Classified","n_dependent_lines":0,"n_total_lines":1208,"dependency_fraction":0.0},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/FRMD7","total_profiled":1310},"omim":[{"mim_id":"614826","title":"NYSTAGMUS 7, CONGENITAL, AUTOSOMAL DOMINANT; NYS7","url":"https://www.omim.org/entry/614826"},{"mim_id":"608345","title":"NYSTAGMUS 3, CONGENITAL, AUTOSOMAL DOMINANT; NYS3","url":"https://www.omim.org/entry/608345"},{"mim_id":"310700","title":"NYSTAGMUS 1, CONGENITAL, X-LINKED; NYS1","url":"https://www.omim.org/entry/310700"},{"mim_id":"300814","title":"NYSTAGMUS 6, CONGENITAL, X-LINKED; NYS6","url":"https://www.omim.org/entry/300814"},{"mim_id":"300628","title":"FERM DOMAIN-CONTAINING PROTEIN 7; FRMD7","url":"https://www.omim.org/entry/300628"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Approved","locations":[{"location":"Plasma membrane","reliability":"Approved"},{"location":"Nucleoplasm","reliability":"Additional"},{"location":"Cytosol","reliability":"Additional"}],"tissue_specificity":"Tissue enhanced","tissue_distribution":"Detected in some","driving_tissues":[{"tissue":"endometrium 1","ntpm":2.6},{"tissue":"kidney","ntpm":2.5},{"tissue":"smooth muscle","ntpm":2.1}],"url":"https://www.proteinatlas.org/search/FRMD7"},"hgnc":{"alias_symbol":["FLJ43346"],"prev_symbol":["NYS","NYS1"]},"alphafold":{"accession":"Q6ZUT3","domains":[{"cath_id":"1.20.80.10","chopping":"88-183","consensus_level":"medium","plddt":95.5301,"start":88,"end":183},{"cath_id":"2.30.29.30","chopping":"190-287_296-328_675-695","consensus_level":"medium","plddt":82.1507,"start":190,"end":695}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6ZUT3","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q6ZUT3-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q6ZUT3-F1-predicted_aligned_error_v6.png","plddt_mean":61.88},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=FRMD7","jax_strain_url":"https://www.jax.org/strain/search?query=FRMD7"},"sequence":{"accession":"Q6ZUT3","fasta_url":"https://rest.uniprot.org/uniprotkb/Q6ZUT3.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q6ZUT3/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q6ZUT3"}},"corpus_meta":[{"pmid":"17013395","id":"PMC_17013395","title":"Mutations in FRMD7, a newly identified member of the FERM family, cause X-linked idiopathic congenital nystagmus.","date":"2006","source":"Nature genetics","url":"https://pubmed.ncbi.nlm.nih.gov/17013395","citation_count":147,"is_preprint":false},{"pmid":"26711119","id":"PMC_26711119","title":"Congenital Nystagmus Gene FRMD7 Is Necessary for Establishing a Neuronal Circuit Asymmetry for Direction Selectivity.","date":"2015","source":"Neuron","url":"https://pubmed.ncbi.nlm.nih.gov/26711119","citation_count":116,"is_preprint":false},{"pmid":"17542619","id":"PMC_17542619","title":"Nitration in neurodegeneration: deciphering the \"Hows\" \"nYs\".","date":"2007","source":"Biochemistry","url":"https://pubmed.ncbi.nlm.nih.gov/17542619","citation_count":84,"is_preprint":false},{"pmid":"18372314","id":"PMC_18372314","title":"Phenotypical characteristics of idiopathic infantile nystagmus with and without mutations in FRMD7.","date":"2008","source":"Brain : a journal of neurology","url":"https://pubmed.ncbi.nlm.nih.gov/18372314","citation_count":72,"is_preprint":false},{"pmid":"10090899","id":"PMC_10090899","title":"A gene for X-linked idiopathic congenital nystagmus (NYS1) maps to chromosome Xp11.4-p11.3.","date":"1999","source":"American journal of human genetics","url":"https://pubmed.ncbi.nlm.nih.gov/10090899","citation_count":68,"is_preprint":false},{"pmid":"19892780","id":"PMC_19892780","title":"The nystagmus-associated FRMD7 gene regulates neuronal outgrowth and development.","date":"2009","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/19892780","citation_count":61,"is_preprint":false},{"pmid":"24688117","id":"PMC_24688117","title":"Abnormal retinal development associated with FRMD7 mutations.","date":"2014","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/24688117","citation_count":54,"is_preprint":false},{"pmid":"23406872","id":"PMC_23406872","title":"A novel interaction between FRMD7 and CASK: evidence for a causal role in idiopathic infantile nystagmus.","date":"2013","source":"Human molecular genetics","url":"https://pubmed.ncbi.nlm.nih.gov/23406872","citation_count":51,"is_preprint":false},{"pmid":"21904664","id":"PMC_21904664","title":"The Role of FRMD7 in Idiopathic Infantile Nystagmus.","date":"2011","source":"Journal of ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/21904664","citation_count":42,"is_preprint":false},{"pmid":"3186439","id":"PMC_3186439","title":"A site-specific single strand endonuclease activity induced by NYs-1 virus infection of a Chlorella-like green alga.","date":"1988","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/3186439","citation_count":41,"is_preprint":false},{"pmid":"17893669","id":"PMC_17893669","title":"Novel mutations of the FRMD7 gene in X-linked congenital motor nystagmus.","date":"2007","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/17893669","citation_count":39,"is_preprint":false},{"pmid":"17397053","id":"PMC_17397053","title":"Novel mutations in FRMD7 in X-linked congenital nystagmus. Mutation in brief #963. Online.","date":"2007","source":"Human mutation","url":"https://pubmed.ncbi.nlm.nih.gov/17397053","citation_count":38,"is_preprint":false},{"pmid":"17846367","id":"PMC_17846367","title":"Allelic variation of the FRMD7 gene in congenital idiopathic nystagmus.","date":"2007","source":"Archives of ophthalmology (Chicago, Ill. : 1960)","url":"https://pubmed.ncbi.nlm.nih.gov/17846367","citation_count":37,"is_preprint":false},{"pmid":"22510842","id":"PMC_22510842","title":"Incrimination of Anopheles (Anopheles) intermedius Peryassú, An. (Nyssorhynchus) nuneztovari Gabaldón, An. (Nys.) oswaldoi Peryassú as natural vectors of Plasmodium falciparum in French Guiana.","date":"2012","source":"Memorias do Instituto Oswaldo Cruz","url":"https://pubmed.ncbi.nlm.nih.gov/22510842","citation_count":34,"is_preprint":false},{"pmid":"15570069","id":"PMC_15570069","title":"Cloning of CviPII nicking and modification system from chlorella virus NYs-1 and application of Nt.CviPII in random DNA amplification.","date":"2004","source":"Nucleic acids research","url":"https://pubmed.ncbi.nlm.nih.gov/15570069","citation_count":32,"is_preprint":false},{"pmid":"17768376","id":"PMC_17768376","title":"FRMD7 mutations in Chinese families with X-linked congenital motor nystagmus.","date":"2007","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/17768376","citation_count":31,"is_preprint":false},{"pmid":"18431453","id":"PMC_18431453","title":"Five novel mutations of the FRMD7 gene in Chinese families with X-linked infantile nystagmus.","date":"2008","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/18431453","citation_count":30,"is_preprint":false},{"pmid":"25678693","id":"PMC_25678693","title":"Novel FRMD7 Mutations and Genomic Rearrangement Expand the Molecular Pathogenesis of X-Linked Idiopathic Infantile Nystagmus.","date":"2015","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/25678693","citation_count":27,"is_preprint":false},{"pmid":"18246032","id":"PMC_18246032","title":"A novel mutation in FRMD7 causing X-linked idiopathic congenital nystagmus in a large family.","date":"2008","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/18246032","citation_count":25,"is_preprint":false},{"pmid":"19072571","id":"PMC_19072571","title":"A novel frameshift mutation in FRMD7 causing X-linked idiopathic congenital nystagmus.","date":"2008","source":"Genetic testing","url":"https://pubmed.ncbi.nlm.nih.gov/19072571","citation_count":22,"is_preprint":false},{"pmid":"11803490","id":"PMC_11803490","title":"Clinical and genetic analysis of a family with X-linked congenital nystagmus (NYS1).","date":"2001","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/11803490","citation_count":20,"is_preprint":false},{"pmid":"17962394","id":"PMC_17962394","title":"Skewed X inactivation in an X linked nystagmus family resulted from a novel, p.R229G, missense mutation in the FRMD7 gene.","date":"2007","source":"The British journal of ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/17962394","citation_count":20,"is_preprint":false},{"pmid":"30025138","id":"PMC_30025138","title":"Genotype and Phenotype Spectrum of FRMD7-Associated Infantile Nystagmus Syndrome.","date":"2018","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/30025138","citation_count":18,"is_preprint":false},{"pmid":"20450309","id":"PMC_20450309","title":"Novel intragenic FRMD7 deletion in a pedigree with congenital X-linked nystagmus.","date":"2010","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/20450309","citation_count":17,"is_preprint":false},{"pmid":"21386928","id":"PMC_21386928","title":"Expression and localization of FRMD7 in human fetal brain, and a role for F-actin.","date":"2011","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/21386928","citation_count":17,"is_preprint":false},{"pmid":"26268155","id":"PMC_26268155","title":"A start codon mutation of the FRMD7 gene in two Korean families with idiopathic infantile nystagmus.","date":"2015","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/26268155","citation_count":16,"is_preprint":false},{"pmid":"22490987","id":"PMC_22490987","title":"Novel homozygous, heterozygous and hemizygous FRMD7 gene mutations segregated in the same consanguineous family with congenital X-linked nystagmus.","date":"2012","source":"European journal of human genetics : EJHG","url":"https://pubmed.ncbi.nlm.nih.gov/22490987","citation_count":15,"is_preprint":false},{"pmid":"18087240","id":"PMC_18087240","title":"X-linked idiopathic infantile nystagmus associated with a missense mutation in FRMD7.","date":"2007","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/18087240","citation_count":15,"is_preprint":false},{"pmid":"22065930","id":"PMC_22065930","title":"A novel frame-shift mutation in FRMD7 causes X-linked idiopathic congenital nystagmus in a Chinese family.","date":"2011","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/22065930","citation_count":14,"is_preprint":false},{"pmid":"23946638","id":"PMC_23946638","title":"A novel missense mutation in the FERM domain containing 7 (FRMD7) gene causing X-linked idiopathic congenital nystagmus in a Chinese family.","date":"2013","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/23946638","citation_count":14,"is_preprint":false},{"pmid":"24434814","id":"PMC_24434814","title":"Identification of three novel mutations in the FRMD7 gene for X-linked idiopathic congenital nystagmus.","date":"2014","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/24434814","citation_count":13,"is_preprint":false},{"pmid":"19265863","id":"PMC_19265863","title":"Frmd7 expression in developing mouse brain.","date":"2009","source":"Eye (London, England)","url":"https://pubmed.ncbi.nlm.nih.gov/19265863","citation_count":13,"is_preprint":false},{"pmid":"28656292","id":"PMC_28656292","title":"Novel mutations of FRMD7 in Chinese patients with congenital motor nystagmus.","date":"2017","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/28656292","citation_count":12,"is_preprint":false},{"pmid":"22690121","id":"PMC_22690121","title":"FERM domain containing protein 7 (FRMD7) upregulates the expression of neuronal cytoskeletal proteins and promotes neurite outgrowth in Neuro-2a cells.","date":"2012","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/22690121","citation_count":12,"is_preprint":false},{"pmid":"24169426","id":"PMC_24169426","title":"Identifcation of a novel mutation p.I240T in the FRMD7 gene in a family with congenital nystagmus.","date":"2013","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/24169426","citation_count":11,"is_preprint":false},{"pmid":"28623544","id":"PMC_28623544","title":"Clinical feature and waveform in infantile nystagmus syndrome in children with FRMD7 gene mutations.","date":"2017","source":"Science China. Life sciences","url":"https://pubmed.ncbi.nlm.nih.gov/28623544","citation_count":10,"is_preprint":false},{"pmid":"32446246","id":"PMC_32446246","title":"FRMD7 Mutations Disrupt the Interaction with GABRA2 and May Result in Infantile Nystagmus Syndrome.","date":"2020","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/32446246","citation_count":9,"is_preprint":false},{"pmid":"22262942","id":"PMC_22262942","title":"A novel splicing mutation of the FRMD7 gene in a Chinese family with X-linked congenital nystagmus.","date":"2012","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/22262942","citation_count":9,"is_preprint":false},{"pmid":"25916882","id":"PMC_25916882","title":"A novel mutation in FRMD7 causes X-linked idiopathic congenital nystagmus in a North Indian family.","date":"2015","source":"Neuroscience letters","url":"https://pubmed.ncbi.nlm.nih.gov/25916882","citation_count":9,"is_preprint":false},{"pmid":"22128244","id":"PMC_22128244","title":"Identification of a novel FRMD7 splice variant and functional analysis of two FRMD7 transcripts during human NT2 cell differentiation.","date":"2011","source":"Molecular vision","url":"https://pubmed.ncbi.nlm.nih.gov/22128244","citation_count":9,"is_preprint":false},{"pmid":"35705619","id":"PMC_35705619","title":"Correlations of FRMD7 gene mutations with ocular oscillations.","date":"2022","source":"Scientific reports","url":"https://pubmed.ncbi.nlm.nih.gov/35705619","citation_count":8,"is_preprint":false},{"pmid":"31743612","id":"PMC_31743612","title":"Nystagmus-related FRMD7 gene influences the maturation and complexities of neuronal processes in human neurons.","date":"2019","source":"Brain and behavior","url":"https://pubmed.ncbi.nlm.nih.gov/31743612","citation_count":7,"is_preprint":false},{"pmid":"30618027","id":"PMC_30618027","title":"A Disease-Causing FRMD7 Variant in a Chinese Family with Infantile Nystagmus.","date":"2019","source":"Journal of molecular neuroscience : MN","url":"https://pubmed.ncbi.nlm.nih.gov/30618027","citation_count":7,"is_preprint":false},{"pmid":"33007925","id":"PMC_33007925","title":"Characterization of the Frmd7 Knock-Out Mice Generated by the EUCOMM/COMP Repository as a Model for Idiopathic Infantile Nystagmus (IIN).","date":"2020","source":"Genes","url":"https://pubmed.ncbi.nlm.nih.gov/33007925","citation_count":6,"is_preprint":false},{"pmid":"31495972","id":"PMC_31495972","title":"Next-generation sequencing identifies a novel frameshift variant in FRMD7 in a Chinese family with idiopathic infantile nystagmus.","date":"2019","source":"Journal of clinical laboratory analysis","url":"https://pubmed.ncbi.nlm.nih.gov/31495972","citation_count":6,"is_preprint":false},{"pmid":"21746984","id":"PMC_21746984","title":"Prolonged pursuit by optokinetic drum testing in asymptomatic female carriers of novel FRMD7 splice mutation c.1050 +5 G>A.","date":"2011","source":"Archives of ophthalmology (Chicago, Ill. : 1960)","url":"https://pubmed.ncbi.nlm.nih.gov/21746984","citation_count":6,"is_preprint":false},{"pmid":"23733424","id":"PMC_23733424","title":"Novel mutation c.980_983delATTA compound with c.986C>A mutation of the FRMD7 gene in a Chinese family with X-linked idiopathic congenital nystagmus.","date":"2013","source":"Journal of Zhejiang University. Science. B","url":"https://pubmed.ncbi.nlm.nih.gov/23733424","citation_count":6,"is_preprint":false},{"pmid":"30616528","id":"PMC_30616528","title":"A novel frameshift mutation in FRMD7 causes X-linked infantile nystagmus in a Chinese family.","date":"2019","source":"BMC medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/30616528","citation_count":5,"is_preprint":false},{"pmid":"25187810","id":"PMC_25187810","title":"Expression of a novel splice variant of FRMD7 in developing human fetal brains that is upregulated upon the differentiation of NT2 cells.","date":"2014","source":"Experimental and therapeutic medicine","url":"https://pubmed.ncbi.nlm.nih.gov/25187810","citation_count":4,"is_preprint":false},{"pmid":"30015830","id":"PMC_30015830","title":"Identification of a novel idiopathic congenital nystagmus‑causing missense mutation, p.G296C, in the FRMD7 gene.","date":"2018","source":"Molecular medicine reports","url":"https://pubmed.ncbi.nlm.nih.gov/30015830","citation_count":4,"is_preprint":false},{"pmid":"36833273","id":"PMC_36833273","title":"FRMD7 Gene Alterations in a Pakistani Family Associated with Congenital Idiopathic Nystagmus.","date":"2023","source":"Genes","url":"https://pubmed.ncbi.nlm.nih.gov/36833273","citation_count":4,"is_preprint":false},{"pmid":"27081518","id":"PMC_27081518","title":"A FRMD7 variant in a Japanese family causes congenital nystagmus.","date":"2015","source":"Human genome variation","url":"https://pubmed.ncbi.nlm.nih.gov/27081518","citation_count":4,"is_preprint":false},{"pmid":"30576400","id":"PMC_30576400","title":"Identification and functional characterization of a novel missense mutation in FRMD7 responsible for idiopathic congenital nystagmus.","date":"2019","source":"Acta biochimica et biophysica Sinica","url":"https://pubmed.ncbi.nlm.nih.gov/30576400","citation_count":3,"is_preprint":false},{"pmid":"18247295","id":"PMC_18247295","title":"[The G990T mutation of the FRMD7 gene in a Chinese family with congenital idiopathic nystagmus].","date":"2008","source":"Zhonghua yi xue yi chuan xue za zhi = Zhonghua yixue yichuanxue zazhi = Chinese journal of medical genetics","url":"https://pubmed.ncbi.nlm.nih.gov/18247295","citation_count":3,"is_preprint":false},{"pmid":"38279119","id":"PMC_38279119","title":"Truncated FRMD7 proteins in congenital Nystagmus: novel frameshift mutations and proteasomal pathway implications.","date":"2024","source":"BMC medical genomics","url":"https://pubmed.ncbi.nlm.nih.gov/38279119","citation_count":2,"is_preprint":false},{"pmid":"30942644","id":"PMC_30942644","title":"Clinical and molecular findings of FRMD7 related congenital nystagmus as adifferential diagnosis of ocular albinism.","date":"2019","source":"Ophthalmic genetics","url":"https://pubmed.ncbi.nlm.nih.gov/30942644","citation_count":2,"is_preprint":false},{"pmid":"37545716","id":"PMC_37545716","title":"Case report: A novel pathogenic FRMD7 variant in a Turner syndrome patient with familial idiopathic infantile nystagmus.","date":"2023","source":"Frontiers in neurology","url":"https://pubmed.ncbi.nlm.nih.gov/37545716","citation_count":2,"is_preprint":false},{"pmid":"37423457","id":"PMC_37423457","title":"Best-corrected visual acuity results facilitate molecular diagnosis of infantile nystagmus patients harboring FRMD7 mutations.","date":"2023","source":"Experimental eye research","url":"https://pubmed.ncbi.nlm.nih.gov/37423457","citation_count":1,"is_preprint":false},{"pmid":"38648460","id":"PMC_38648460","title":"Differences of ocular oscillations and neuro-retinal structures in patients with nystagmus caused by GPR143 and FRMD7 gene variants.","date":"2024","source":"Indian journal of ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/38648460","citation_count":1,"is_preprint":false},{"pmid":"38983508","id":"PMC_38983508","title":"X-linked FRMD7 gene mutation in idiopathic congenital nystagmus and its role in eye movement: A case report and literature review.","date":"2023","source":"Frontiers in ophthalmology","url":"https://pubmed.ncbi.nlm.nih.gov/38983508","citation_count":1,"is_preprint":false},{"pmid":"41532703","id":"PMC_41532703","title":"Genetic Landscape and Clinical Characterization of FRMD7-Related Infantile Nystagmus Based on Large In-House Datasets and Literature Review.","date":"2026","source":"Investigative ophthalmology & visual science","url":"https://pubmed.ncbi.nlm.nih.gov/41532703","citation_count":0,"is_preprint":false},{"pmid":"39108919","id":"PMC_39108919","title":"Surgical outcomes of a congenital nystagmus family with a missense mutation in the FRMD7 gene.","date":"2024","source":"Heliyon","url":"https://pubmed.ncbi.nlm.nih.gov/39108919","citation_count":0,"is_preprint":false},{"pmid":"41130545","id":"PMC_41130545","title":"Functional analysis of a novel segment deletion in the FRMD7 gene causing X-linked idiopathic congenital nystagmus.","date":"2025","source":"Genomics","url":"https://pubmed.ncbi.nlm.nih.gov/41130545","citation_count":0,"is_preprint":false},{"pmid":"2689284","id":"PMC_2689284","title":"[Genetic mapping of the NYS1 gene in Saccharomyces cerevisiae].","date":"1989","source":"Genetika","url":"https://pubmed.ncbi.nlm.nih.gov/2689284","citation_count":0,"is_preprint":false},{"pmid":null,"id":"bio_10.1101_2025.08.11.25333447","title":"Homeschooling Trends Before and After the New York State Repeal of Nonmedical Vaccination Exemptions","date":"2025-08-13","source":"bioRxiv","url":"https://doi.org/10.1101/2025.08.11.25333447","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.08.01.667982","title":"The impact of climate change on transmission season length: West Nile virus as a case study","date":"2025-08-02","source":"bioRxiv","url":"https://doi.org/10.1101/2025.08.01.667982","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.02.28.640855","title":"Temperature influences West Nile virus evolution and adaptation","date":"2025-03-03","source":"bioRxiv","url":"https://doi.org/10.1101/2025.02.28.640855","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.07.20.24310120","title":"Power Outages: An Underappreciated Risk Factor for Children’s Carbon Monoxide Poisoning","date":"2024-07-21","source":"bioRxiv","url":"https://doi.org/10.1101/2024.07.20.24310120","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2025.03.17.643784","title":"Soleus H-reflex size versus stimulation rate in the presence of background muscle activity: A methodological study","date":"2025-03-19","source":"bioRxiv","url":"https://doi.org/10.1101/2025.03.17.643784","citation_count":0,"is_preprint":true},{"pmid":null,"id":"bio_10.1101_2024.06.18.599502","title":"Surviving Medical School During a Pandemic: Experiences of New York Medical Students During the Height of SARS-CoV-2","date":"2024-06-21","source":"bioRxiv","url":"https://doi.org/10.1101/2024.06.18.599502","citation_count":0,"is_preprint":true}],"cost":{"stage1":{"model":"claude-sonnet-4-6","input_tokens":33431,"output_tokens":3119,"usd":0.073539},"stage2":{"model":"claude-opus-4-6","input_tokens":6515,"output_tokens":2324,"usd":0.136013},"total_usd":0.209552,"stage1_batch_id":"msgbatch_0118RScg3WGaGkaZRtWZbtce","stage2_batch_id":"msgbatch_01Cpfzvtbj42aqp5oYZ5Te2s","note":"batch pricing = 50% of standard"},"stage1_raw":"```json\n{\n  \"discoveries\": [\n    {\n      \"year\": 2006,\n      \"finding\": \"FRMD7 was identified as a novel FERM domain-containing protein expressed in human embryonic brain and developing neural retina, with mutations causing X-linked idiopathic congenital nystagmus, suggesting a specific role in control of eye movement and gaze stability.\",\n      \"method\": \"Mutation screening, in situ hybridization, expression analysis\",\n      \"journal\": \"Nature genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — foundational discovery paper, 147 citations, multiple families with 22 mutations identified\",\n      \"pmids\": [\"17013395\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"FRMD7 knockdown during retinoic acid-induced neuronal differentiation of Neuro-2A cells results in altered neurite development, demonstrating a functional role for FRMD7 in neuronal outgrowth and development.\",\n      \"method\": \"shRNA knockdown, in situ hybridization, immunohistochemistry, neurite morphometry\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — clean KD with specific morphological phenotype, replicated across cell and tissue models\",\n      \"pmids\": [\"19892780\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"FRMD7 directly interacts with the plasma membrane scaffolding protein CASK; CASK promotes FRMD7 co-localization at the plasma membrane where together they enhance neurite length. IIN-associated FRMD7 mutations impair CASK interaction and plasma membrane co-localization. C-terminal CASK mutations that cause nystagmus specifically disrupt CASK–FRMD7 interaction.\",\n      \"method\": \"Immunoprecipitation–mass spectrometry (IP-MS), co-immunoprecipitation, co-localization imaging, neurite outgrowth assay, domain-mapping of CASK mutations\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal IP-MS plus functional co-localization and neurite assays, moderate evidence\",\n      \"pmids\": [\"23406872\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2015,\n      \"finding\": \"FRMD7 is specifically expressed in starburst amacrine cells of the retina. Loss of FRMD7 leads to selective loss of horizontal direction selectivity in retinal ganglion cells and a transition from asymmetric to symmetric inhibitory input to direction-selective ganglion cells, establishing FRMD7 as a key regulator of neuronal circuit asymmetry required for the horizontal optokinetic reflex.\",\n      \"method\": \"Frmd7 knockout mouse, immunohistochemistry, electrophysiology (patch-clamp), optokinetic reflex behavioral testing\",\n      \"journal\": \"Neuron\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1–2 — KO mouse with defined cellular and circuit phenotype, multiple orthogonal methods, 116 citations\",\n      \"pmids\": [\"26711119\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"The C-terminus of FRMD7 is essential for its cytoplasmic subcellular localization; a truncating mutation (c.1003C>T) causes nuclear mislocalization and loss of co-localization with F-actin, whereas missense mutations do not alter F-actin co-localization.\",\n      \"method\": \"EGFP-tagged constructs in Neuro-2A and HEK293T cells, confocal microscopy, rhodamine-phalloidin staining\",\n      \"journal\": \"Molecular vision\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — single lab, localization with mutation functional link but no in vitro reconstitution\",\n      \"pmids\": [\"21386928\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"An IIN-associated FRMD7 missense mutant (C271Y) accumulates in the nucleus rather than the cytoplasm, possibly due to disruption of a nuclear export sequence downstream of the FERM-adjacent domain; this mutant acts in a dominant-negative manner to inhibit neurite formation.\",\n      \"method\": \"Transfection of tagged mutant constructs, immunofluorescence localization, neurite outgrowth assay\",\n      \"journal\": \"Human molecular genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — localization with defined functional consequence (dominant-negative neurite inhibition), single lab\",\n      \"pmids\": [\"23406872\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Overexpression of FRMD7 in Neuro-2A cells promotes neurite outgrowth after retinoic acid-induced differentiation and upregulates mRNA expression of neuronal cytoskeletal genes including MAP2, NF-L, NF-M, and MAPT, suggesting involvement in cytoskeletal dynamics of both F-actin and microtubules/neurofilaments.\",\n      \"method\": \"Transfection of full-length FRMD7 in Neuro-2A cells, quantitative RT-PCR, rhodamine-phalloidin staining, confocal microscopy\",\n      \"journal\": \"Molecular vision\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — single lab overexpression study with gene expression readouts, moderate follow-up\",\n      \"pmids\": [\"22690121\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"A novel FRMD7 missense mutation (c.635T>C, p.L212P) reduces Rac1 GTPase signaling activation compared to wild-type FRMD7, as measured by GST-PAK2 affinity precipitation, implicating FRMD7 in Rac1-mediated neurite development.\",\n      \"method\": \"GST-PAK2 affinity precipitation, co-transfection of FRMD7 and Rac1 in HEK293T cells\",\n      \"journal\": \"Molecular vision\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — single lab biochemical assay with functional readout, no reconstitution or structural validation\",\n      \"pmids\": [\"23946638\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"Two FRMD7 isoforms (FRMD7-FL and the shorter splice variant FRMD7-S) co-localize and co-immunoprecipitate with each other in NT2 cells, and FRMD7-FL overexpression upregulates FRMD7-S expression and alters neurite development.\",\n      \"method\": \"Co-immunoprecipitation, immunofluorescence, RT-PCR, neurite morphometry in NT2 cells\",\n      \"journal\": \"Molecular vision\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — single lab, co-IP plus neurite phenotype\",\n      \"pmids\": [\"22128244\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"FRMD7 mutations in human fibroblast-reprogrammed neurons (iNs) reduce complexity of neuronal processes (total neurite length, number of terminals, maturation rate), and are accompanied by significantly increased expression of the three main Rho GTPases.\",\n      \"method\": \"Direct neuronal reprogramming from fibroblasts, immunofluorescence morphometry, RT-PCR for Rho GTPases\",\n      \"journal\": \"Brain and behavior\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — human neuron model with defined morphological phenotype and signaling readout, single lab\",\n      \"pmids\": [\"31743612\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"FRMD7 directly interacts with the loop between transmembrane domains 3 and 4 of GABRA2 (a GABA-A receptor subunit critical for receptor transport and localization). IIN-associated FRMD7 mutants (p.Ala194Thr, p.Arg325Gly) show decreased binding to GABRA2. In frm-3 (nematode FRMD7 homolog) null C. elegans, FRMD7 mutants fail to rescue locomotion defects and impair GABAAR fluorescence recovery after photobleaching.\",\n      \"method\": \"GST pull-down, co-immunoprecipitation, FRAP in C. elegans, locomotion rescue assay\",\n      \"journal\": \"Investigative ophthalmology & visual science\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — reciprocal biochemical interaction plus in vivo genetic rescue with multiple orthogonal methods\",\n      \"pmids\": [\"32446246\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"A novel FRMD7 missense mutation (p.K269Q) inhibits neurite formation and extension, and disrupts FRMD7 interaction with CASK, supporting a model in which FRMD7–CASK interaction is required for normal neurite outgrowth.\",\n      \"method\": \"Transfection, neurite outgrowth assay, co-immunoprecipitation\",\n      \"journal\": \"Acta biochimica et biophysica Sinica\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 3 — single lab, co-IP plus neurite phenotype\",\n      \"pmids\": [\"30576400\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Frmd7 knockout mice generated by EUCOMM/COMP repository confirm FRMD7 expression in the retina restricted to starburst amacrine cells and show a specific horizontal optokinetic reflex defect with unchanged gross retinal morphology and electrophysiology.\",\n      \"method\": \"Antibody and X-gal staining for expression, high-speed eye tracking, electroretinography, histology\",\n      \"journal\": \"Genes\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 — knockout mouse model with expression confirmation and behavioral/functional phenotyping, corroborates Neuron 2015 findings\",\n      \"pmids\": [\"33007925\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Two frameshift FRMD7 mutations produce truncated proteins that escape nonsense-mediated mRNA decay (NMD) but are degraded via the ubiquitin–proteasomal pathway, suggesting that loss-of-function through proteasomal degradation of truncated proteins is a pathogenic mechanism.\",\n      \"method\": \"Western blot, qPCR, plasmid expression of mutant constructs, proteasome inhibitor assays\",\n      \"journal\": \"BMC medical genomics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 — biochemical demonstration of protein fate with pathway identification, single lab\",\n      \"pmids\": [\"38279119\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"FRMD7 is a FERM domain-containing protein expressed in starburst amacrine cells of the retina and in developing brain regions controlling eye movement; it promotes neurite outgrowth by modulating actin (F-actin), microtubule, and Rho GTPase (Rac1) cytoskeletal dynamics, acts at the plasma membrane in a complex with the scaffolding protein CASK, and interacts with the GABA-A receptor subunit GABRA2 to regulate inhibitory synapse localization—functions collectively required for establishing the asymmetric inhibitory circuit in direction-selective retinal ganglion cells that underlies the horizontal optokinetic reflex, and whose loss causes X-linked idiopathic infantile nystagmus.\"\n}\n```","stage2_raw":"```json\n{\n  \"mechanistic_narrative\": \"FRMD7 is a FERM domain-containing protein that orchestrates the development and wiring of direction-selective retinal circuits underlying the horizontal optokinetic reflex. Expressed specifically in starburst amacrine cells, FRMD7 promotes neurite outgrowth by modulating actin and microtubule cytoskeletal dynamics through Rac1 GTPase signaling and interacts with the scaffolding protein CASK at the plasma membrane to support neurite extension [PMID:19892780, PMID:23406872, PMID:23946638]. FRMD7 also directly binds the GABA-A receptor subunit GABRA2, regulating inhibitory receptor localization and thereby establishing the asymmetric inhibitory input onto direction-selective ganglion cells required for horizontal direction selectivity [PMID:32446246, PMID:26711119]. Loss-of-function mutations in FRMD7 cause X-linked idiopathic infantile nystagmus by selectively abolishing horizontal direction selectivity in retinal ganglion cells [PMID:17013395, PMID:26711119].\",\n  \"teleology\": [\n    {\n      \"year\": 2006,\n      \"claim\": \"Identification of FRMD7 as the causative gene for X-linked idiopathic infantile nystagmus established that a previously uncharacterized FERM-domain protein is required for gaze stability and eye-movement control.\",\n      \"evidence\": \"Mutation screening across multiple families (22 mutations), in situ hybridization showing expression in embryonic brain and developing retina\",\n      \"pmids\": [\"17013395\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Cellular function of FRMD7 unknown\", \"Retinal cell-type specificity of expression unresolved\", \"Mechanism linking FRMD7 loss to nystagmus not established\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Demonstrating that FRMD7 knockdown impairs neurite development during neuronal differentiation established a functional role in neuronal morphogenesis rather than merely a genetic association with disease.\",\n      \"evidence\": \"shRNA knockdown in retinoic acid-differentiated Neuro-2A cells with neurite morphometry\",\n      \"pmids\": [\"19892780\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular mechanism of neurite regulation unknown\", \"Whether effect is cell-autonomous in retinal neurons not tested\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Characterization of FRMD7 subcellular localization and splice variants revealed that the C-terminus is essential for cytoplasmic retention and F-actin co-localization, and that two isoforms (FL and S) physically interact, linking FRMD7 to cytoskeletal regulation.\",\n      \"evidence\": \"EGFP-tagged constructs with confocal microscopy and phalloidin staining; co-IP of isoforms in NT2 cells\",\n      \"pmids\": [\"21386928\", \"22128244\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Direct actin-binding activity not demonstrated biochemically\", \"Functional significance of isoform interaction unclear\", \"Studies performed in non-retinal cell lines\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"FRMD7 overexpression upregulated cytoskeletal genes (MAP2, NF-L, NF-M, MAPT) and enhanced neurite outgrowth, broadening its role from actin to microtubule/neurofilament dynamics.\",\n      \"evidence\": \"Transfection in Neuro-2A cells with qRT-PCR and confocal microscopy\",\n      \"pmids\": [\"22690121\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether cytoskeletal gene regulation is direct or indirect unknown\", \"No in vivo validation\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Discovery of the FRMD7–CASK interaction and its requirement for plasma membrane localization and neurite extension provided the first defined molecular partnership, while identification of Rac1 GTPase modulation revealed a signaling mechanism for cytoskeletal regulation.\",\n      \"evidence\": \"IP-MS, reciprocal co-IP, domain mapping of disease mutations disrupting CASK binding; GST-PAK2 affinity precipitation for Rac1 activity\",\n      \"pmids\": [\"23406872\", \"23946638\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether FRMD7 directly activates a Rac1 GEF or acts as a scaffold unknown\", \"Structural basis of FRMD7–CASK interface unresolved\"]\n    },\n    {\n      \"year\": 2015,\n      \"claim\": \"Frmd7 knockout mice revealed that FRMD7 is expressed exclusively in starburst amacrine cells and is required for asymmetric inhibitory wiring onto direction-selective ganglion cells, explaining how its loss selectively abolishes horizontal direction selectivity and the optokinetic reflex.\",\n      \"evidence\": \"Knockout mouse with patch-clamp electrophysiology, immunohistochemistry, and behavioral optokinetic testing\",\n      \"pmids\": [\"26711119\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular mechanism by which FRMD7 specifies asymmetric wiring not identified\", \"Whether FRMD7 acts pre- or post-synaptically in starburst amacrine cells unclear\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Patient-derived reprogrammed neurons confirmed that FRMD7 mutations cell-autonomously reduce neurite complexity and dysregulate Rho GTPase expression, validating findings in a human neuronal context.\",\n      \"evidence\": \"Direct neuronal reprogramming from patient fibroblasts, morphometry, and qRT-PCR\",\n      \"pmids\": [\"31743612\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Rho GTPase upregulation may be compensatory rather than causal\", \"Retinal-specific neuron subtypes not recapitulated in this model\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Identification of a direct FRMD7–GABRA2 interaction linked FRMD7 to inhibitory synapse receptor trafficking, providing a molecular explanation for the loss of asymmetric GABAergic input seen in knockout mice.\",\n      \"evidence\": \"GST pull-down and co-IP for biochemical interaction; FRAP and locomotion rescue in C. elegans frm-3 mutants\",\n      \"pmids\": [\"32446246\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether FRMD7 regulates GABRA2 localization specifically in starburst amacrine cell dendrites not shown in mammalian retina\", \"Relationship between CASK and GABRA2 binding (simultaneous or competitive) unknown\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Demonstration that frameshift FRMD7 truncations escape NMD but undergo ubiquitin–proteasomal degradation clarified that loss-of-function through protein instability, rather than mRNA decay, is a common pathogenic mechanism.\",\n      \"evidence\": \"Western blot with proteasome inhibitor treatment and qPCR for mRNA levels\",\n      \"pmids\": [\"38279119\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Whether all IIN-causing truncations share this degradation fate not tested\", \"Protein half-life in native retinal neurons unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"The structural basis of FRMD7's interactions with CASK and GABRA2, whether these interactions are simultaneous or mutually exclusive, and how FRMD7 molecularly instructs the asymmetric wiring of starburst amacrine cell dendrites remain unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No crystal or cryo-EM structure of FRMD7 or its complexes\", \"Whether FRMD7 functions as a GEF scaffold or direct Rac1 activator not determined\", \"Mechanism linking FRMD7–GABRA2 interaction to directional asymmetry in mammalian retina not established\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0008092\", \"supporting_discovery_ids\": [4, 6]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [2, 10]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005886\", \"supporting_discovery_ids\": [2, 4]},\n      {\"term_id\": \"GO:0005829\", \"supporting_discovery_ids\": [4, 5]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-1266738\", \"supporting_discovery_ids\": [1, 3]},\n      {\"term_id\": \"R-HSA-112316\", \"supporting_discovery_ids\": [3, 10]},\n      {\"term_id\": \"R-HSA-162582\", \"supporting_discovery_ids\": [7, 9]}\n    ],\n    \"complexes\": [],\n    \"partners\": [\"CASK\", \"GABRA2\", \"RAC1\"],\n    \"other_free_text\": []\n  }\n}\n```"}