Multiple origins of the mtDNA 7472insC mutation associated with hearing loss and neurological dysfunction

Several mtDNA mutations have been reported in families with bath syndromic and non-syndromic hearing loss. One such mutation is the heteroplasmic 7472 insC in the tRNA(Ser(UCN)) gene which has been found in six families, all f rom Western Europe. However, it was not clear if this distribution was due to a common founder effect or chance sampling of several unrelated families , the 7472insC mutation having occurred multiple times. Haplotype analysis of all six families supports the latter notion. This confirms the pathogeni city of the 7472insC mutation and suggests it may exist in other population s where it may prove to be a small but significant cause of hearing loss, p articularly when neurological symptoms are also present.