Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0162671 (MELAS)
 587 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Peripheral neuropathy is one of the clinical manifestations of the MELAS (mitochondrial encephalopathy with lactic acidosis and stroke-like episodes) syndrome, but its frequency and phenotypic variability have not been properly characterised. We therefore studied the clinical and electrophysiological features of peripheral neuropathy in 32 patients with the 3243A > G mutation in mitochondrial DNA by using clinical examination, assessment of Neuropathy Symptom Score, Neuropathy Disability Score, and electrophysiological examinations. Seven patients (22 %; 95 % confidence interval, 9-40 %) fulfilled the electrodiagnostic criteria for polyneuropathy. Mixed axon loss and demyelinating sensorimotor neuropathy was the most common type of polyneuropathy, while one patient presented with uniform demyelinating sensorimotor polyneuropathy. Sensory more than motor neuropathy was diagnosed in four patients. Clinically and electrophysiologically confirmed carpal tunnel syndrome (CTS) occurred in three patients (9.4 %), suggesting a higher prevalence than in the general population. Patients with neuropathy were in general more severely affected than those without neuropathy, although no correlation was found between the presence of neuropathy and the degree of mutant heteroplasmy in muscle. Higher age and male gender were associated with an increased risk of neuropathy. Our results show that peripheral neuropathy is not uncommon in patients with the 3243A > G mutation, and they also may have an increased risk of CTS.
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PMID:Peripheral neuropathy in patients with the 3243A>G mutation in mitochondrial DNA. 1257 54

Mitochondrial disorders (MIDs) occasionally manifest as polyneuropathy either as the dominant feature or as one of many other manifestations (inherited mitochondrial neuropathy). MIDs in which polyneuropathy is the dominant feature, include NARP syndrome due to the transition m.8993T>, CMT2A due to MFN2 mutations, CMT2K and CMT4A due to GDAP1 mutations, and axonal/demyelinating neuropathy with external ophthalmoplegia due to POLG1 mutations. MIDs in which polyneuropathy is an inconstant feature among others is the MELAS syndrome, MERRF syndrome, LHON, Mendelian PEO, KSS, Leigh syndrome, MNGIE, SANDO; MIRAS, MEMSA, AHS, MDS (hepato-cerebral form), IOSCA, and ADOA syndrome. In the majority of the cases polyneuropathy presents in a multiplex neuropathy distribution. Nerve conduction studies may reveal either axonal or demyelinated or mixed types of neuropathies. If a hereditary neuropathy is due to mitochondrial dysfunction, the management of these patients is at variance from non-mitochondrial hereditary neuropathies. Patients with mitochondrial hereditary neuropathy need to be carefully investigated for clinical or subclinical involvement of other organs or systems. Supportive treatment with co-factors, antioxidants, alternative energy sources, or lactate lowering agents can be tried. Involvement of other organs may require specific treatment. Mitochondrial neuropathies should be included in the differential diagnosis of hereditary neuropathies.
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PMID:Inherited mitochondrial neuropathies. 2140 91