A PCR-RFLP Assay for the A716T Mutation in the WFS1 Gene,a Common Cause of Low-Frequency Sensorineural Hearing Loss

Nonsyndromic low-frequency sensorineural hearing loss (LFSNHL) is an unusual type of hearing loss that affects frequencies at 2,000 Hz and below. Recently, we reported five different heterozygous missense mutations in the Wolfram syndrome gene, WFS1, found to be responsible for LFSNHL in six families. One of the five mutations, A716T, may be a common cause of LFSNHL, as it has been reported in three families to date (Bespalova et al., 2001; Young et al., 2001). We have developed a PCR-based restriction fragment-length polymorphism (RFLP) assay to detect the A716T mutation in a simple, specific test. This method was evaluated with DNA samples from a family in which the A716T mutation was segregating with LFSNHL. This simple assay successfully detected the presence of the A716T mutation in all of the individuals predicted to be affected, based on audiologic results. Therefore, this assay can be routinely used for initial screening of the A716T mutation in patients with LFSNHL, before screening the entire coding region of the WFS1 gene.