A novel mtDNA point mutation in maternally inherited cardiomyopathy.

A novel mtDNA mutation at position nt. 4300 in the tRNAIle gene is associated with hypertrophic cardiomyopathy inherited as a maternal trait. Interestingly, this mutation seems to cause a pure heart disease as opposed to most other mtDNA mutations, which are associated with multisystemic disorders. Hypertrophic cardiomyopathies are genetically heterogeneous, and mtDNA defects should be considered in the differential diagnosis, especially when there is evidence of maternal inheritance.