Genetic Analysis of a Family with Mohr-Tranebjaerg Syndrome

Objective Mohr-Tranebjaerg syndrome (MTS) is a rare X-linked neurodegenerative disorder which usually involving hearing impairment, gradual dystonia, and other symptoms. In this study, we perform analyzed the genetic makeup of a family with this rare Mohr-Tranebjaerg syndrome. Methods We collected the clinical data of the family, did the whole exome sequencing on the proband Ⅲ6 with a rare mutation, and verified the mutation in another affected family member Ⅲ5 and unaffected members Ⅰ1, Ⅰ2, Ⅱ1, Ⅱ5, Ⅱ7, Ⅱ8, Ⅲ7. Results The patients in the family all showed early-onset deafness. More than a couple of affected male members have dystonia with/without mental disorders. Genetic testing results showed the proband Ⅲ6 had a c.133-2delA in TIMM8A (NM_ 004085.3, DDP1), highly likely pathogenic(LP). This variation was detected in affected Ⅲ5 as well as the unaffected females Ⅰ1, Ⅱ5, Ⅱ7. Conclusions MTS caused by the rare TIMM8A mutation, the molecular etiology of the family with this rare disease, is highly consistent with the clinical manifestations and segregation. Other than the deafness, other symptoms varied among the affected family members. Genetic diagnosis for such X-linked diseases can also identify female heterozygotes. Genetic and reproduction counseling can help families in the family planning.