An analysis of a large postlingually deaf family with hereditary non-syndromic profound hearing loss.
We initiated a clinical and genetic linkage study on members of a large Venezuelan family with hereditary hearing loss. A medical history and a physical examination were performed on 30 family members. Audiometry was carried out in 25 subjects, and in 2 additional children auditory brainstem responses were obtained. Additional testing (site-of-lesion, electronystagmography and computed tomography) was also obtained in a few subjects. DNA was extracted from blood samples from 25 family members. The type of deafness in this family is neurosensorial, non-syndromic and postlingual. The average age of onset of deafness is 7 years and there is a rapid progression leading to profound deafness. Deafness is possibly of cochlear origin and there is no associated vestibular pathology. Analysis of the pedigree discloses a maternal pattern of inheritance with a significant female predominance, compatible with a mutation of the mitochondrial DNA. The molecular DNA analysis for the known mitochondrial mutations are discussed.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004272:DNA, Mitochondrial / Q000235:genetics*; D003638:Deafness / Q000235:genetics*; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D009154:Mutation; D010375:Pedigree; D014687:Venezuela