Ainhi D. Ha and Kaitlyn L. Parratt contributed equally to this article.
Article first published online: 26 JUN 2012
Copyright © 2012 Movement Disorder Society
Volume 27, Issue 8, pages 1034–1040, July 2012
How to Cite
Ha, A. D., Parratt, K. L., Rendtorff, N. D., Lodahl, M., Ng, K., Rowe, D. B., Sue, C. M., Hayes, M. W., Tranebjærg, L. and Fung, V. S.C. (2012), The phenotypic spectrum of dystonia in Mohr–Tranebjaerg syndrome. Mov. Disord., 27: 1034–1040. doi: 10.1002/mds.25033
Funding agencies: The Lundbeck Foundation (grant no. 32011) and Widex AS provided financial support to the Audiogenetic Research Group at ICMM. The molecular studies took place at the Wilhelm Johannsen Centre for Functional Genome Research, which was established by grants from the National Research Foundation in Denmark.
Relevant conflicts of interest/financial disclosures: Nothing to report.
Full financial disclosures and author roles may be found in the online version of this article.
- Issue published online: 17 JUL 2012
- Article first published online: 26 JUN 2012
- Manuscript Accepted: 8 APR 2012
- Manuscript Revised: 17 MAR 2012
- Manuscript Received: 5 JAN 2012
- Mohr–Tranebjaerg syndrome;
- deafness-dystonia-optic neuronopathy (DDON) syndrome;
- generalized dystonia;
- sensorineural hearing impairment
Mohr–Tranebjaerg syndrome (MTS) is an X-linked recessive disorder characterized by deafness and dystonia. However the phenotypic expression of dystonia has not been systematically defined. We report clinical, neurophysiological, and ophthalmological data on 6 subjects from 3 Australian kindreds, including 2 with novel mutations, together with a systematic review of the literature, in order to define the phenotypic expression of dystonia. Profound hearing impairment in affected males develops by infancy and precedes the development of dystonia, which varies in time of onset from the first to the sixth decades, with a peak in the second and third decades. Dystonia in MTS tends to be focal, segmental, or multifocal in distribution at onset, with a predilection for the upper body, variably involving the head, neck, and upper limbs. The majority of patients have progression or generalization of their dystonia regardless of age of onset. Within our 3 kindreds, we observed relative intrafamilial homogeneity but interfamilial variation. The median time to the development of moderate-severely disabling dystonia in these subjects was 11 years. Associated features included progressive cognitive decline, pyramidal signs, and in 1 patient, gait freezing and postural instability. Optic atrophy and cortical visual impairment were both observed. We report for the first time a female patient who developed multiple disabling neurological complications of MTS. Our findings more clearly define and expand the phenotype of both the dystonia and other neurological features of MTS and have implications for the diagnosis and management of this condition. © 2012 Movement Disorder Society