Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0013421 (dystonia)
 8,418 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

X linked recessive deafness accounts for only 1.7% of all childhood deafness. Only a few of the at least 28 different X linked syndromes associated with hearing impairment have been characterised at the molecular level. In 1960, a large Norwegian family was reported with early onset progressive sensorineural deafness, which was indexed in McKusick as DFN-1, McKusick 304700. No associated symptoms were described at that time. This family has been restudied clinically. Extensive neurological, neurophysiological, neuroradiological, and biochemical, as well as molecular techniques, have been applied to characterise the X linked recessive syndrome. The family history and extensive characterisation of 16 affected males in five generations confirmed the X linked recessive inheritance and the postlingual progressive nature of the sensorineural deafness. Some obligate carrier females showed signs of minor neuropathy and mild hearing impairment. Restudy of the original DFN-1 family showed that the deafness is part of a progressive X linked recessive syndrome, which includes visual disability leading to cortical blindness, dystonia, fractures, and mental deficiency. Linkage analysis indicated that the gene was linked to locus DXS101 in Xq22 with a lod score of 5.37 (zero recombination). Based on lod-1 support interval of the multipoint analysis, the gene is located in a region spanning from 5 cM proximal to 3 cM distal to this locus. As the proteolipid protein gene (PLP) is within this region and mutations have been shown to be associated with non-classical PMD (Pelizaeus-Merzbacher disease), such as complex X linked hereditary spastic paraplegia, PLP may represent a candidate gene for this disorder. This family represents a new syndrome (Mohr-Tranebjaerg syndrome, MTS) and provides significant new information about a new X linked recessive sydromic type of deafness which was previously thought to be isolated deafness.
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PMID:A new X linked recessive deafness syndrome with blindness, dystonia, fractures, and mental deficiency is linked to Xq22. 764 52

In 1960, progressive sensorineural deafness (McKusick 304,700, DFN-1) was shown to be X-linked based on a description of a large Norwegian pedigree. More recently, it was shown that this original DFN-1 family represented a new type of recessive neurodegenerative syndrome characterized by postlingual progressive sensorineural deafness as the first presenting symptom in early childhood, followed by progressive dystonia, spasticity, dysphagia, mental deterioration, paranoia and cortical blindness. This new disorder, termed Mohr-Tranebjaerg syndrome (referred to here as DFN-1/MTS) was mapped to the Xq21.3-Xq22 region2. Using positional information from a patient with a 21-kb deletion in chromosome Xq22 and sensorineural deafness along with dystonia, we characterized a novel transcript lying within the deletion as a candidate for this complex syndrome. We now report small deletions in this candidate gene in the original DFN-1/MTS family, and in a family with deafness, dystonia and mental deficiency but not blindness. This gene, named DDP (deafness/ dystonia peptide), shows high levels of expression in fetal and adult brain. The DDP protein demonstrates striking similarity to a predicted Schizosaccharomyces pombe protein of no known function. Thus, is it likely that the DDP gene encodes an evolutionarily conserved novel polypeptide necessary for normal human neurological development.
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PMID:A novel X-linked gene, DDP, shows mutations in families with deafness (DFN-1), dystonia, mental deficiency and blindness. 884 Nov 89

Mohr-Tranebjaerg syndrome (MTS/DFN-1) or deafness/dystonia syndrome results from a mutation in deafness/dystonia protein 1/translocase of mitochondrial inner membrane 8a (DDP1/TIMM8a). DDP1/TIMM8a is similar to a family of yeast proteins in the mitochondrial intermembrane space which mediate the import and insertion of inner membrane proteins. We now show that TIMM8a assembles in a 70 kDa complex in the intermembrane space with TIMM13. DDP1/TIMM8a is not detectable in fibroblasts derived from a patient with a missense mutation in the DDP1/TIMM8a gene; the point mutation results in cysteine-66 being changed to tryptophan-66 in the conserved 'twin CX(3)C' motif. The corresponding mutation in yeast translocase of inner membrane 8p (Tim8p) yields an unstable protein that does not assemble with yeast Tim13p. DDP1/TIMM8a, when expressed with TIMM13 in yeast mitochondria lacking the Tim8p-Tim13p complex, restores Tim23p import, and TIMM8a and TIMM13 can be cross-linked to the hTim23 import intermediate in rat and yeast mitochondria. In a similar manner to Tim8p, TIMM8a seemingly mediates the import of hTim23. Deafness/dystonia syndrome thus may be caused by decreased levels of Tim23 in the mitochondrial inner membrane in affected tissues.
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PMID:Human deafness dystonia syndrome is caused by a defect in assembly of the DDP1/TIMM8a-TIMM13 complex. 1187 42

The biogenesis of the mitochondrial inner membrane is dependent on two distinct 70 kDa protein complexes. TIMM8a partners with TIMM13 in the mitochondrial intermembrane space to form a 70 kDa complex and facilitates the import of the inner membrane substrate TIMM23. We have identified a new class of substrates, citrin and aralar1, which are Ca2+-binding aspartate/glutamate carriers (AGCs) of the mitochondrial inner membrane, using cross-linking and immunoprecipitation assays in isolated mitochondria. The AGCs function in the aspartate-malate NADH shuttle that moves reducing equivalents from the cytosol to the mitochondrial matrix. Mohr-Tranebjaerg syndrome (MTS/DFN-1, deafness/dystonia syndrome) results from a mutation in deafness/dystonia protein 1/translocase of mitochondrial inner membrane 8a (DDP1/TIMM8a) and loss of the 70 kDa complex. A lymphoblast cell line derived from an MTS patient had decreased NADH levels and defects in mitochondrial protein import. Protein expression studies indicate that DDP1 and TIMM13 show non-uniform expression in mammals, and expression is prominent in the large neurons in the brain, which is in agreement with the expression pattern of aralar1. Thus, insufficient NADH shuttling, linked with changes in Ca2+ concentration, in sensitive cells of the central nervous system might contribute to the pathologic process associated with MTS.
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PMID:The calcium-binding aspartate/glutamate carriers, citrin and aralar1, are new substrates for the DDP1/TIMM8a-TIMM13 complex. 1525 20

The deafness-dystonia syndrome (DDS) or Mohr-Tranebjaerg syndrome (MTS, MIM 304700) is a rare X-linked recessive neurological disorder resulting from loss-of-function mutations in the nuclear DDP1/TIMM8A gene, involved in the transport and sorting of proteins to the mitochondrial inner membrane. A Mohr-Tranebjaerg patient and his mother were subjected to clinical and molecular studies. Screening of mutations were performed in TIMM8A, TIMM13, and other mitochondrial protein transport genes by conformation sensitive gel electrophoresis (CSGE), followed by direct DNA sequencing of tissue samples from the patient. Mitochondrial DNA of the patient was also sequenced at the genes for COX subunits and some mitochondrial tRNAs. Respiratory chain activities in a muscle biopsy and cultured fibroblasts from the patient were assessed using biochemical methods. mRNA expression of TIMM8A and TIMM13 was determined by RT-PCR in cultured fibroblasts. We identified a new case of Mohr-Tranebjaerg syndrome and report the characteristics of a new pathogenic de novo mutation (c.112C>T, pGln38X) in the TIMM8A gene. Biochemical measures of respiratory chain complex activities in muscle biopsy and fibroblasts did not show a major deficiency or alteration. mRNA expression studies demonstrated increased TIMM8A mRNA levels in cultured fibroblasts from the patient. Phenotypic differences among published cases seem not to be related with the mutation location or type. Our results support the idea that dysfunctions of mitochondrial protein transport, in addition to OXPHOS deficiency, can be the basis of important mitochondrial pathologies.
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PMID:Molecular genetics of a patient with Mohr-Tranebjaerg Syndrome due to a new mutation in the DDP1 gene. 1799 2

Mohr-Tranebjaerg syndrome is a rare X-linked condition characterized by the association of dystonia and progressive postlingual sensorineural hearing impairment. Here we report the clinical and genetic findings in a Spanish patient with MTS carrying a novel mutation in the DDP1 (deafness-dystonia peptide 1) gene, which encodes TIMM8a, a component of the mitochondrial protein translocation system. The phenotypic variability observed in patients with Mohr-Tranebjaerg syndrome suggests the involvement of modifier factors which may modulate the clinical manifestations of the syndrome.
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PMID:A Spanish sporadic case of deafness-dystonia (Mohr-Tranebjaerg) syndrome with a novel mutation in the gene encoding TIMM8a, a component of the mitochondrial protein translocase complexes. 1895 32