Combination of mtDNA mutations in a patient with a mitochondrial multisystem syndrome.

We report a patient who manifested a heterogeneous clinical presentation, including hypertrophic cardiomyopathy and hypothyroidism, with initially limited central nervous system involvement, and who harbored the mitochondrial (mt)DNA A3243G mutation. MtDNA analysis also revealed deleted genomes in muscle and blood. This atypical molecular combination may have influenced the clinical phenotype.