Hearing impairment and neurological dysfunction associated with a mutation in the mitochondrial tRNASer(UCN) gene.

TitleHearing impairment and neurological dysfunction associated with a mutation in the mitochondrial tRNASer(UCN) gene.
Publication TypeJournal Article
Year of Publication1999
AuthorsVerhoeven, K, Ensink, RJ, Tiranti, V, Huygen, PL, Johnson, DF, Schatteman, I, Van Laer, L, Verstreken, M, Van de Heyning, P, Fischel-Ghodsian, N, Zeviani, M, Cremers, CW, Willems, PJ, Van Camp, G
JournalEur J Hum Genet
Date Published1999 Jan
KeywordsAminoglycosides, DNA, Mitochondrial, Female, Hearing Loss, Sensorineural, Humans, Male, Mutation, Pedigree, RNA, Transfer, Ser

We studied a large Dutch family with maternally inherited, progressive, sensorineural hearing loss in 27 patients. Only in a single family member was the hearing loss accompanied by neurological symptoms including ataxia and dysarthria. DNA analysis of the mitochondrial genome revealed the insertion of a C at nucleotide position 7472 in the tRNASer(UCN) gene (7472insC mutation). We determined the percentage of mutant DNA (heteroplasmy) in blood from all family members, and found no correlation between hearing loss and leucocyte heteroplasmy. The 7472insC mutation was previously identified in a smaller family from Sicily with sensorineural hearing loss in 9 family members, six of them also presenting neurologically with ataxia and myoclonus. The presence of the 7472insC mutation in two different pedigrees strongly supports its pathogenicity. However, the interfamilial difference in penetrance of the neurologic abnormalities is most likely to be strongly influenced by secondary factors different from the 7472insC mutation, as heteroplasmy or age of the patients were similar in both families. This mutation should therefore be analysed in families with maternally inherited hearing loss, irrespective of whether the hearing loss is non-syndromic or accompanied by neurologic abnormalities.

Alternate JournalEur. J. Hum. Genet.
Citation Key10.1038/sj.ejhg.5200247
PubMed ID10094190
Grant ListR01DC01402 / DC / NIDCD NIH HHS / United States
R01DC02273 / DC / NIDCD NIH HHS / United States