ADGRV1 and hearing loss disorder: It is the most common subtype, accounting for nearly two-thirds of cases, and is primarily due to biallelic variants in USH2A, ADGRV1, or WHRN. 10USH types 3 and 4 are rare and seen in specific populations (eg, Finnish and Ashkenazi Jewish); they are characterized by childhood-onset hearing loss and adult-onset RP, secondary to pathogenic variants in CLRN1 and ARSG, among others.6