title: Non-syndromic Hearing Impairment in a Hungarian Family with the m.7510T>C Mutation of Mitochondrial tRNA(Ser(UCN)) and Review of Published Cases.
abstract: The m.7510T>C mitochondrial DNA (mtDNA) mutation is a tRNA(Ser(UCN)) alteration leading to matrilineal isolated hearing impairment. The current paper reviews the available reports on the m.7510T>C mtDNA mutation, with special attention to phenotypic variations and haplogroup background. A Hungarian family, the fourth family reported in the literature, is presented, in which analysis of three generations with bilateral isolated hearing loss revealed the m.7510T>C tRNA(Ser(UCN)) mutation in homoplasmic form in the affected members. Haplogroup analysis verified an unnamed subgroup of mitochondrial haplogroup H. Previously reported Spanish and North American Caucasian families belong to different subgroups of haplogroup H. Analyzing our biobank of Hungarian patients with sensorineural hearing loss, we did not detect this mutation in any other patient, nor was it found in Caucasian haplogroup H control samples. Comparing the cases reported so far, there is interfamilial variablity in the age of onset, accompanying symptoms, and haplogroup background. Our case adds further genetic evidence for the pathogenicity of the m.7510T>C mutation and underlines the need to include full mtDNA sequencing in the screening for unexplained hearing loss.
authors: Department of Medical Genetics, University of Pécs, József A. út 7, Pécs, H-7623, Hungary. komlosi.katalin@pte.hu.
authors: Katalin
authors: K
authors: Komlósi
authors: Department of Medical Genetics, University of Pécs, József A. út 7, Pécs, H-7623, Hungary.
authors: Anita
authors: A
authors: Maász
authors: Department of Medical Genetics, University of Pécs, József A. út 7, Pécs, H-7623, Hungary.
authors: Péter
authors: P
authors: Kisfali
authors: Department of Medical Genetics, University of Pécs, József A. út 7, Pécs, H-7623, Hungary.
authors: Kinga
authors: K
authors: Hadzsiev
authors: Department of Medical Genetics, University of Pécs, József A. út 7, Pécs, H-7623, Hungary.
authors: Judit
authors: J
authors: Bene
authors: Department of Medical Genetics, University of Pécs, József A. út 7, Pécs, H-7623, Hungary.
authors: Béla I
authors: BI
authors: Melegh
authors: Department of Medical Genetics, University of Pécs, József A. út 7, Pécs, H-7623, Hungary.
authors: Béla
authors: B
authors: Melegh
authors: 2nd Department of Pediatrics, Semmelweis University, Budapest, Hungary.
authors: Mária
authors: M
authors: Ablonczy
authors: 2nd Department of Pediatrics, Semmelweis University, Budapest, Hungary.
authors: Krisztina
authors: K
authors: Németh
authors: 2nd Department of Pediatrics, Semmelweis University, Budapest, Hungary.
authors: György
authors: G
authors: Fekete