title: Extended screening for major mitochondrial DNA point mutations in patients with hereditary hearing loss.
abstract: Hearing loss (HL) is the most common sensory disorder in humans. Many patients with mitochondrial diseases have sensorineural HL (SNHL). The HL of these patients manifests as a consequence of either syndromic or nonsyndromic mitochondrial diseases. Furthermore, the phenotypes vary among patients even if they are carrying the same mutation. Therefore, these features make it necessary to analyze every presumed mutation in patients with hereditary HL, but the extensive analysis of various mutations is laborious. We analyzed 373 patients with suspected hereditary HL by using an extended suspension-array screening system for major mitochondrial DNA (mtDNA) mutations, which can detect 32 other mtDNA mutations in addition to the previously analyzed 29 mutations. In the present study, we detected 2 different mtDNA mutations among these 373 patients; m.7444G>A in the MT-CO1 gene and m.7472insC in the MT-TS1 gene in 1 patient (0.3%) for each. As these two patients had no clinical features other than HL, they had not been suspected of having mtDNA mutations. This extended screening system together with the previous one is useful for the genetic diagnosis and epidemiological study of both syndromic and nonsyndromic HL.
authors.affiliation: Department of Otolaryngology, Tokyo Metropolitan Geriatric Hospital and Institute of Gerontology, Tokyo, Japan.
authors.forename: Tomofumi
authors.initials: T
authors.lastname: Kato
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Nishigaki
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Noguchi
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Fuku
authors.forename: Taku
authors.initials: T
authors.lastname: Ito
authors.forename: Eri
authors.initials: E
authors.lastname: Mikami
authors.forename: Ken
authors.initials: K
authors.lastname: Kitamura
authors.forename: Masashi
authors.initials: M
authors.lastname: Tanaka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015374:Biosensing Techniques; D002648:Child; D002675:Child, Preschool; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D050259:Genes, Mitochondrial / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D034381:Hearing Loss / Q000235:genetics*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D017354:Point Mutation / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013535:Suspensions; D055815:Young Adult
chemical_list: D004272:DNA, Mitochondrial; D013535:Suspensions