Adult-onset hypertrophic cardiomyopathy manifested as initial major presentation of mitochondrial disease with A-to-G 3243 tRNA Leu(UUR) point mutation

Mitochondrial diseases such as mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS), myoclonus epilepsy with ragged-red fibers (MERRF), and Kearns–Sayre syndrome are manifested due to reduced production of Adenosine triphosphate (ATP) in mitochondria. The disorders in mitochondria comprise a heterogeneous group of diseases with multi-system involvement. Although mitochondrial cardiomyopathy is a common manifestation of mitochondrial respiratory chain disorders, cardiac involvement rarely causes the initial symptoms or the major clinical manifestation in previous literature reports, especially less mentioned in adult cases. Here we reported a 36-year-old male of hypertrophic cardiomyopathy which was diagnosed in his thirties, and he was treated as having heart failure for about years. He presented with progressive symptoms and signs of heart failure and bilateral lower leg weakness for weeks before admission, and later complicated with respiratory failure during hospitalization. The final diagnosis was mitochondrial disease with A-to-G 3243 tRNA Leu(UUR) point mutation by gene analysis and ragged-red fibers in muscle biopsy.