Usher syndrome type 1

Usher syndrome type 1 (USH1) is the most severe form of Usher syndrome, a group of autosomal recessive disorders characterized by the combination of sensorineural hearing loss and progressive vision loss due to retinitis pigmentosa (RP). USH1 is defined by profound congenital bilateral sensorineural deafness, vestibular areflexia (absent balance function), and prepubertal onset of retinitis pigmentosa. Children with USH1 are born profoundly deaf and typically experience delayed motor milestones, particularly in sitting and walking independently, due to vestibular dysfunction. Vision loss from retinitis pigmentosa usually begins in childhood or early adolescence, initially presenting as night blindness and progressive constriction of the visual fields, eventually leading to severe visual impairment or blindness. Several genes are associated with USH1, including MYO7A (USH1B, the most common subtype), CDH23 (USH1D), PCDH15 (USH1F), USH1C, USH1G (SANS), and CIB2. These genes encode proteins that play critical roles in the development and maintenance of hair cells in the inner ear and photoreceptor cells in the retina. Mutations in these genes disrupt the structural and functional integrity of both sensory systems. There is currently no cure for Usher syndrome type 1. Management is multidisciplinary and focuses on early intervention. Cochlear implantation is the standard of care for addressing the profound hearing loss and is most effective when performed early in life to support speech and language development. Low-vision aids, orientation and mobility training, and educational support are essential as retinitis pigmentosa progresses. Gene therapy clinical trials are underway for certain subtypes, particularly USH1B (MYO7A), offering hope for future treatments targeting the underlying genetic cause. Genetic counseling is recommended for affected families.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

Common questions about Usher syndrome type 1