A Homozygous Founder ELAC2 Variant in Kuwaiti Infants With Fatal Cardiomyopathy and Refractory Severe Lactic Acidosis: A Retrospective Review of the Clinical, Cardiological and Molecular Findings

BACKGROUND: Infantile-onset cardiomyopathy due to mitochondrial dysfunction is a severe condition frequently associated with poor prognosis. Biallelic pathogenic variants in ELAC2, an essential mitochondrial tRNA processing gene, have been implicated in this phenotype. This study investigates the clinical and genetic spectrum of ELAC2-related disease in a national cohort from Kuwait. METHODS: We conducted a retrospective cohort study using data from the Kuwait Medical Genetics Center registry, including individuals with genetically confirmed or clinically suspected ELAC2-related cardiomyopathy. Clinical, metabolic, and molecular data were reviewed. Exome sequencing or targeted mutation testing was performed in affected individuals and at-risk family members. RESULTS: A total of 34 individuals from 23 consanguineous families were identified, of whom 30 were genetically confirmed to harbor the homozygous ELAC2 founder variant c.460T>C; p.(Phe154Leu). All individuals presented in infancy with severe cardiomyopathy and refractory lactic acidosis. Neurological involvement was observed in 39% of cases. The majority exhibited hypertrophic cardiomyopathy, with variable dilated features and pericardial effusion. The disease course was fatal in all, with most patients dying in infancy. CONCLUSION: This is the largest single-country cohort reported to date with ELAC2-related mitochondrial cardiomyopathy, raising the global case total to over 70. The uniform presence of the Phe154Leu variant across unrelated Bedouin families highlights a strong founder effect. Given the rapid disease progression and high mortality, we recommend targeted ELAC2 screening in infants with idiopathic cardiomyopathy and persistent lactic acidosis, particularly in consanguineous populations. Premarital carrier testing and early family counseling should be prioritized to support preventive strategies.