| USH Type | Gene symbol | Protein name | Chromosome location (GRCh38) | Disease / subtype OMIM ID | Protein / gene function | Reported mutation frequency / prevalence contribution |
|---|---|---|---|---|---|---|
| USH1 | **MYO7A** | Myosin VIIA | chr11:77128246–77215241 | USH1B / **276900**; gene **276903** | Actin-based motor protein essential for hair-bundle structure/function and photoreceptor/periciliary transport | Major USH1 gene; reported to account for **>50% of USH1** in one review; also listed as **21% of all genetically characterized USH cases** in a large cohort summary (pqac-00000003, pqac-00000010) |
| USH1 | **USH1C** | Harmonin | chr11:17493895–17544416 | USH1C / **276904**; gene **605242** | Scaffold protein in the Usher interactome; organizes protein complexes in stereocilia and photoreceptors | Rare cause; estimated **~2% of all USH cases** in a cohort summary (pqac-00000010) |
| USH1 | **CDH23** | Cadherin 23 | chr10:71396934–71815947 | USH1D / **601067**; gene **605516** | Cell-adhesion protein; component of stereociliary links important for mechanotransduction | Uncommon cause; estimated **~6% of all USH cases** in a cohort summary (pqac-00000010) |
| USH1 | **PCDH15** | Protocadherin 15 | chr10:53802771–55627942 | USH1F / **602083**; gene **605514** | Cell-adhesion / tip-link associated protein required for stereocilia cohesion and sensory transduction | Uncommon cause; estimated **~3% of all USH cases** in a cohort summary (pqac-00000010) |
| USH1 | **USH1G** | SANS | chr17:73223675–73258264 | USH1G / **606943**; gene **607696** | Scaffold/adaptor protein within the Usher protein network in hair cells and photoreceptors | Very rare; estimated **~1% of all USH cases** in a cohort summary (pqac-00000010) |
| USH2 | **USH2A** | Usherin | chr1:215622891–216423448 | USH2A / **276901**; gene **608400** | Extracellular matrix / transmembrane-associated Usher complex component at photoreceptor periciliary membrane and base of hair bundles | Principal USH2 gene; reported to cause **~80% of USH2** in one review, **50% of all USH cases** in another cohort summary, and **50% of all USH2 cases** in a focused USH2 review (pqac-00000003, pqac-00000007, pqac-00000010) |
| USH2 | **ADGRV1** | Adhesion G protein-coupled receptor V1 (VLGR1) | chr5:89942634–90549316 | USH2C / **605472**; gene **602851** | Very large adhesion GPCR; part of the USH2 complex in hair bundles and photoreceptor periciliary region | Less common USH2 cause; estimated **~5% of all USH cases** in a cohort summary (pqac-00000010) |
| USH2 | **WHRN** | Whirlin | chr9:117382790–117481605 | USH2D / **611383**; gene **607928** | PDZ-domain scaffold protein in the USH2 complex; supports stereocilia elongation/organization and photoreceptor protein networks | Rare USH2 cause; estimated **~0.4% of all USH cases** in a cohort summary (pqac-00000010) |
| USH3 | **CLRN1** | Clarin-1 | chr3:150928506–150975693 | USH3A / **276902**; gene **606397** | Four-transmembrane protein implicated in hair-cell and photoreceptor synaptic/sensory function | Main confirmed USH3 gene; estimated **~2% of all USH cases** overall, but markedly enriched in Finnish and Ashkenazi Jewish populations where **>40% of USH can be USH3** (subtype prevalence, not gene share) (pqac-00000006, pqac-00000010) |
| Contested / no longer generally accepted as confirmed | **CIB2** | Calcium and integrin-binding family member 2 | — | Formerly proposed USH1J / gene **605564** | Initially proposed Usher-related protein; later reviews note it is **no longer generally considered a confirmed Usher gene** | Included in some older 10-gene lists, but multiple reviews caution against counting it among confirmed causative genes (pqac-00000001, pqac-00000006) |


*Table: This table summarizes the confirmed major Usher syndrome genes by clinical subtype, with protein names, genomic locations, OMIM identifiers, core functions, and reported contribution to disease burden. It is useful for quickly comparing the relative importance and biological roles of USH1, USH2, and USH3 genes.*