A new family with the mitochondrial tRNAGLU gene mutation m.14709T>C presenting with hydrops fetalis

BackgroundIn the heterogeneous group of mitochondrial disorders, patients with the same genotype can show different phenotypes and the same phenotype can be caused by different genotypes. We describe a family with the m.14709T>C mutation and a clinical presentation of hydrops fetalis, in contrast to previous reports in which patients presented with myopathy and/or diabetes mellitus.AimTo identify a mutation in the mtDNA of a family with a heterogeneous clinical presentation.MethodsBoth biochemical and molecular analyses were performed.ResultsBiochemical results showed a decreased complex I and IV activity in muscle tissue of the patients. A mosaic-staining pattern for complex I in the patients’ fibroblasts was revealed using immunocytochemistry. Molecular analyses identified the m.14709T>C mutation in the mitochondrial encoded tRNAGlu gene.ConclusionWe report 2 siblings with the m.14709T>C mutation in the mitochondrial tRNAGlu gene. The first patient showed hydrops fetalis, a new presentation within the clinical spectrum of this mutation, and the other a known presentation namely mild myopathy.