De Novo ACTN2 Variant in a Chinese Neonate With Left Ventricular Non‐Compaction and Metabolic Disturbances: A Rare Case Report

Left ventricular non-compaction (LVNC) is a rare cardiomyopathy characterized by prominent trabeculations and deep recesses. Neonatal cases, particularly with severe metabolic disturbances, are uncommon. We report a 2-day-old neonate with LVNC and dilated cardiomyopathy, presenting recurrent heart failure associated with hyperkalemia, metabolic acidosis, hyperlactatemia, and hypoglycemia. Management included mechanical ventilation, metabolic correction, and heart failure therapy, leading to improved cardiac function. Genetic analysis revealed a de novo heterozygous pathogenic ACTN2 deletion spanning exons 2-6. This case broadens the phenotypic spectrum of ACTN2-related LVNC and suggests a potential link between metabolic disturbances and cardiac deterioration.