Mitochondrial DNA variations associated with hypertrophic cardiomyopathy

Area of Science:

• Genetics
• Cardiology
• Mitochondrial Biology

Background:

• Hypertrophic cardiomyopathy (HCM) is a genetic heart muscle disease characterized by left ventricular hypertrophy.
• Mitochondrial DNA (mtDNA) mutations and haplogroups are implicated in various diseases.
• Understanding genetic factors in HCM is crucial for diagnosis and treatment.

Purpose of the Study:

• To investigate the role of mitochondrial DNA variations and haplogroups in the phenotype of hypertrophic cardiomyopathy among Indian patients.
• To identify novel mtDNA mutations associated with HCM.
• To explore the potential impact of these mutations on cardiac energy production.

Main Methods:

• Complete mitochondrial DNA (mtDNA) sequencing was performed on 114 clinically characterized HCM patients.
• Analysis included identification of novel variations, disease-associated mutations, and private mutations.
• In silico predictions were used to assess the pathogenicity of identified mutations.

Main Results:

• The study identified 28 novel mtDNA variations, 25 disease-associated mutations, and 50 private mutations.
• Approximately 11.40% of HCM patients carried novel non-synonymous and/or MT-tRNA variations.
• Two specific mutations (m.4797C>M and m.8728T>Y) were found in a heteroplasmic state, with in silico analysis suggesting potential pathogenicity affecting energy production.
• No association was found between mitochondrial haplogroups and HCM in this cohort.

Conclusions:

• Novel mitochondrial DNA variations, including potentially pathogenic mutations, are present in Indian patients with hypertrophic cardiomyopathy.
• These variations may contribute to HCM pathogenesis by affecting cardiac energy metabolism.
• Mitochondrial haplogroups do not appear to be associated with HCM in the studied Indian population.