A novel mitochondrial point mutation in a maternal pedigree with sensorineural deafness

TLDR

The mutation destroys an XbaI site, a region where a second mutation at np 7444 has been associated with Leber’s hereditary optic neuropathy. We identified a novel T→C mutation at np 7445 in tRNA‑ser(UCN) that also alters the COI stop codon; it was present in all 13 affected family members, predominantly homoplasmic, and absent in >600 controls and other deafness pedigrees. © 1994 Wiley‑Liss, Inc.

Abstract

We have detected a novel mitochondrial mutation in a maternal pedigree, at least 13 of whose members have sensorineural hearing loss of varying severity, but who exhibit no other pathological features. The mutation, at np 7445, converts the 3′ terminal T residue of tRNA-ser(UCN) to a C, and also brings about a silent alteration to the COI stop codon. The mutation destroys an XbaI site, within which a second mutation, at np 7444, has previously been reported in association with Leber's hereditary optic neuropathy. Predominantly mutant mtDNA was found in all 13 family members surveyed, whether or not they are overtly affected by deafness, and some individuals appeared homoplasmic, within the limits of detection. The novel mutation was not found in over 600 normal controls, nor in any of 27 other maternally unrelated individuals with deafness Other mutations found in mitochondrial disorders were also absent from this pedigree. © 1994 Wiley-Liss, Inc.