A novel mutation in a family with non-syndromic sensorineural hearing loss that disrupts the newly characterised OTOF long isoforms.

EDITOR—Around 1 in 1000 children is born or presents in early childhood with a severe hearing impairment. 2 In developed countries, approximately 50% of these cases are attributed to genetic causes and the majority are non-syndromic with an autosomal recessive mode of transmission. Childhood onset nonsyndromic sensorineural hearing loss (NSSNHL) is almost exclusively monogenic. This has facilitated the mapping of over 25 autosomal recessive NSSNHL loci (assigned DFNB) (Hearing Loss Homepage, http:// hgins.uia.ac.be/dnalab/hhh). More recently, positional cloning and candidate gene screening strategies have led to the identification of 10 NSSNHL genes (Hearing Loss Homepage).