Mediterr J Otol 2005:1(3):110-116

Mitochondrial DNA alterations involving position 961 are not sufficient to explain sensorineural hearing loss

Türker Duman, Saniye Tugba Arıcan, Suna Tokgöz Yılmaz, Susan Kupka,  Arti Pandya, Nejat Akar, Armağan Incesulu, Mustafa Tekin
Division of Molecular Pathology and Genetics, Department of Pediatrics; Ankara University School of Medicine, Ankara, 06100, Turkey mtekin@medicine.ankara.edu.tr

OBJECTIVE: We present the results of screening for the m.961delTinsC(n) and m.961T>G alterations among children with SNHL in Turkey.

PATIENTS AND METHODS: We screened 210 unrelated Turkish children with congenital or prelingual-onset sensorineural nonsyndromic hearing loss for the mtDNA m.961delTinsC(n) and m.961T>G alterations, which are related to hearing loss.

RESULTS: One child with m.961delTinsC(n) and 2 children with m.961T>G were identified. Autosomal recessive (rather than mitochondrial) inheritance of the hearing impairment, with multiple affected sibs with normal hearing parents, was the most likely explanation in 2 of these families. There was only one affected child in the third family. Other autosomal recessive deafness genes or loci were not causative DNA changes in one family with the m.961delTinsC(n) mutation.

CONCLUSION: Because hearing subjects carry both changes, the two changes alone are not sufficient to cause deafness, although involvement of nuclear modifiers is also possible.