A nonsynonymous mutation in theWFS1gene in a Finnish family with age-related hearing impairment
Wolfram syndrome (WS) is caused by recessive mutations in the Wolfram syndrome 1 (WFS1) gene. Sensorineural hearing impairment (HI) is a frequent feature in WS and, furthermore, certain mutations in WFS1 cause nonsyndromic dominantly inherited low-frequency sensorineural HI. These two phenotypes are clinically distinct indicating that WFS1 is a reasonable candidate for genetic studies in patients with other phenotypes of HI. Here we have investigated, whether the variation in WFS1 has a pathogenic role in age-related hearing impairment (ARHI). WFS1 gene was investigated in a population sample of 518 Finnish adults born in 1938–1949 and representing variable hearing phenotypes. Identified variants were evaluated with respect to pathogenic potential. A rare mutation predicted to be pathogenic was found in a family with many members with impaired hearing. Twenty members were recruited to a segregation study and a detailed clinical examination. Heterozygous p.Tyr528His variant segregated completely with late-onset HI in which hearing deteriorated first at high frequencies and progressed to mid and low frequencies later in life. We report the first mutation in the WFS1 gene causing late-onset HI with audiogram configurations typical for ARHI. Monogenic forms of ARHI are rare and our results add WFS1 to the short list of such genes.