Usher Syndrome Type 1F
Summary
Usher syndrome type 1F is the most severe form of Usher syndrome — a condition combining congenital profound deafness, vestibular dysfunction (balance problems), and progressive retinitis pigmentosa (vision loss). PCDH15 encodes protocadherin-15, a protein critical for the mechanotransduction apparatus of inner ear hair cells and for photoreceptor structure in the retina.
Practical takeaway
Relevant if your partner is Ashkenazi Jewish. Additionally, PCDH15 variants can interact with variants in other Usher syndrome genes. A carrier test can determine partner status. Realised does not calculate reproductive risk or advise on reproductive decisions.
Evidence detail
What Carrier Status Means For You
You are not affected. One working copy of PCDH15 is sufficient. Standard 25/50/25 recessive inheritance applies.
Population Context
The R245X variant is an Ashkenazi Jewish founder mutation. Usher syndrome overall affects approximately 1 in 6,000-25,000 people. Type 1 (the most severe) accounts for ~35% of all Usher syndrome.
Limitations
23andMe tests 1 PCDH15 variant. Usher syndrome involves 9+ genes. A negative PCDH15 result does not rule out carrier status for other Usher types.