[MIM 276 900, 276 901, 276 902, 276 904, 500 004, 601 067, 602 083, 602 097, 605 472, 606 943, 611 383, 612 632, 614 504, 614 869, 614 990]

Rare: prevalence of about 1/30,000 in Europe. Autosomal recessive transmission. Genetics is heterogeneous. Congenital association of sensorineural hearing loss and retinitis pigmentosa, which causes a progressive loss of vision.

Different types:

-        type 1 (40%) or USH1: profoundly deaf from birth associated with a lack of vestibular reflexes;

• USH1A formerly called French variety associated by mistake to a mutation of the MYO7A gene on chromosome 14
• USH1C Acadian variety ; mutation of harmonin (11p15)
• USH1D : mutation of the CDH 23 gene coding for cadherin-23 (10q21)
• USH1F : mutation of the PCDH15 gene coding forprotocadherin-15 (10q22)
• USH1G : mutation of the SANS gene (17q24-25)
• USH1E : mutation in 21q21
• USH1H : mutation in 15q22-q23
• USH1J : mutation of the CIB2 gene (15q24)
• USH1K : mutation in 10p11.21-q21.1
• USH1D/F : mutation of the CDH23 and PCDH25 genes

-        type 2 (60%) or USH2: progressive deafness (predominantly for the high frequencies) and there is no vestibular interference; based on the causal mutation, one can duistinguish:

• USH2A : mutation of either the USH2A (1q41) or PDZD7 (10q24.31) gene
• USH2C : mutation of the ADGRV1 gene (5q14) or of the ADGRV1 and PDZD7 genes
• USH2D : mutation of the WHRN gene (9q32)

-        type 3 (< 3%) or USH3 : especially in Finland and the Ashkenazi Jewish population; rapidly progressive deafness associated with vestibular disorders in 50% of cases; CLRN1 gene on 3q21-25.

• USH3A : mutation of the CLRN1 gene (3q21-25) ; other mutations of the same gene can produce a non syndromic retinitis pigmentosa  .
• USH3B : mutation of the HARS gene (5q31.3)

Retinitis pigmentosa develops more slowly: discomfort with night vision (lesions at ophthalmoscopy, low voltage or flat ERG), gradual decrease of the visual field and eventually blindness (around the age of 50-70 years).

Anesthetic implications:

anesthetic management of a hearing impaired or deaf child (sometimes with a cochlear implant)

References : 

-         Hawksworth C, Ravury S. 
An audit of anesthesia safety in a pediatric cochlear implantation program. 
Pediatr Anesth 2015; 25: 95-630-5.

Updated: September 2018