Early onset cardiomyopathy associated with the mitochondrial tRNALeu((UUR)) 3271T>C MELAS mutation

Abstract

Mitochondrial disorders are a heterogeneous group of diseases sharing a defect of the oxidative phosphorylation system. Point mutations in the mitochondrial DNA are a common cause of mitochondrial disorders and frequently affect the sequences encoding mitochondrial transfer RNAs. The m.3271T>C mutation in the mitochondrial tRNA(Leu(UUR)) is traditionally reported in patients with clinical features of the mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome and in mitochondrial diabetes. Here we describe the clinical, pathological, and molecular features of an Italian child and his asymptomatic mother, carrying the m.3271T>C mutation in the mitochondrial tRNA(Leu(UUR)) gene, in association with an unusual clinical phenotype dominated by hypertrophic cardiomyopathy and provide review literature of cases with this mutation. To the best of our knowledge, there are no reports describing the association of this mutation with cardiomyopathy, and our cases suggest that the m.3271T>C mutation has to be taken into account in the diagnostic approach of maternally inherited cardiomyopathies.

Keywords: Cardiomyopathy; Mitochondrial-tRNA; m.3271T>C mutation.