MELAS-SYNDROME - CLINICAL, BIOLOGICAL AND MOLECULAR-GENETIC FEATURES

Background - MELAS syndrome is a rare mitochondrial cytopathy; its dia gnosis can be difficult. Case report, - A 6-month-old boy presented wi th febrile seizures, possibly due to viral meningitis. At 7 months, he developed myoclonia and ''brain attacks'' and, subsequently, myocloni cal attacks, regression of psychomotor and mental acquisitions, and pr ogressive visual loss. The ratio oi lactatorachia/lactacidemia was inc reased. The molecular generic analysis showed an heteroplasmic point m utation with A-to-G mutation at nucleotide 3243 of the mitochondrial t RNA(leu) (UUR) gene, He was the second child of a mother having freque nt headaches. His great aunt, a sister of his maternal grandmother, wa s mentally retarded and had frequent epileptic seizures and hemiparesy since her childhood. Conclusion. - Any unusual neurological symptom, particularly when combined with ''illegitimate'' symptoms, should lead to search for a mitochondrial cytopathy. (C) 1998 Elsevier, Paris.