Mitochondrial dementia: a sporadic case of progressive cognitive and behavioral decline with hearing loss due to the rare m.3291T>C MELAS mutation.

TitleMitochondrial dementia: a sporadic case of progressive cognitive and behavioral decline with hearing loss due to the rare m.3291T>C MELAS mutation.
Publication TypeJournal Article
Year of Publication2011
AuthorsSalsano, E, Giovagnoli, ARita, Morandi, L, Maccagnano, C, Lamantea, E, Marchesi, C, Zeviani, M, Pareyson, D
JournalJ Neurol Sci
Volume300
Issue1-2
Pagination165-8
Date Published2011 Jan 15
ISSN1878-5883
KeywordsAdult, Cognition Disorders, Dementia, Female, Hearing Loss, Humans, MELAS Syndrome, Mutation, RNA, Transfer, Leu, Wolff-Parkinson-White Syndrome
Abstract

We report the case of a 23-year-old Italian female harboring the rare m.3291T>C mutation in the MT-TL1 gene, that encodes the mitochondrial transfer RNA for leucine 1 (UUA/G). MT-TL1 mutations usually cause the MELAS (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) syndrome. Our patient, however, suffered from a non-syndromic mitochondrial disorder (MID), clinically characterized by progressive cognitive and behavioral decline, and hearing loss; brain MRI disclosed diffuse supratentorial and infratentorial atrophy; EKG revealed a Wolff-Parkinson-White syndrome; combined neuroleptic and antidepressant treatment markedly improved her behavioral symptoms. This case expands the clinical spectrum of non-syndromic MIDs, and further confirms that no obvious genotype-phenotype correlation exists for the m.3291T>C DNA mutation; indeed, this mutation has been previously reported in a Japanese child, who suffered from MELAS, and in an Italian child, who presented an apparently isolated mild myopathy. Moreover, it supports the hypothesis that at least in MT-TL1-related MIDs, dementia may be caused by a progressive neurodegenerative process, rather than by injury accumulation due to stroke-like episodes. Finally, our case suggests that common neuroleptic and antidepressant drugs may be clinically efficacious in the management of psychiatric symptoms associated with MIDs.

DOI10.1016/j.jns.2010.09.022
Alternate JournalJ. Neurol. Sci.
Citation Key10.1016/j.jns.2010.09.022
PubMed ID20943236