Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Mohr-Tranebjaerg syndrome
Introduction
Overview
Overview
Mohr-Tranebjaerg syndrome (MTS) (formerly DFN-1) is an X-linked neurodegenerative syndrome.[1]
Clinical features
Clinical features
- Prelingual or postlingual sensorineural hearing loss
- Progressive dystonia and visual impairment
- Psychiatric symptoms, cognitive impairment and behavioural problems
Early-onset deafness is the only pathognomonic symptom; all other clinical signs vary in their degree of severity and clinical course.
Genetics
Genetics
- The underlying genetic defects are found in the TIMM8A/DDP1 gene located on chromosome Xq22.
- DDP1/TIMM8A encodes a small polypeptide of 97 amino acid residues, the deafness-dystonia peptide 1 (DDP1). Functional studies revealed that DDP1 is localized to the mitochondria, and plays a role in the import of nuclear-encoded preproteins into the mitochondrial inner membrane.
- Loss of DDP1 leads to impairment of specific mitochondrial functions and, subsequently, to degeneration of neuronal cells.
Treatment
Treatment
As with other mitochondrial disorders, there is no specific treatment for MTS.
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aditya Govindavarjhulla, M.B.B.S. [2]