PPCS (phosphopantothenoylcysteine synthetase) catalyzes the second step in coenzyme A biosynthesis from vitamin B5, conjugating cysteine to 4'-phosphopantothenate to form 4-phosphopantothenoylcysteine and showing preference for ATP over CTP as a cosubstrate. The enzyme functions as a homodimer in the cytoplasm and nucleus. Biallelic loss-of-function variants in PPCS cause autosomal recessive dilated cardiomyopathy, which is often fatal and distinguishes PPCS-deficiency from other CoA biosynthesis disorders (such as PANK2 and COASY mutations) that manifest with neurodegeneration and brain iron accumulation 1. PPCS-deficiency represents a relatively new disease entity with unclear pathogenesis and no targeted therapy currently available. Patient-derived induced pluripotent stem cells have been generated to enable cellular modeling and screening of potential therapeutic compounds 1. The involvement of PPCS in cardiac function aligns with CoA's essential role in energy metabolism, making this gene critical for cardiomyocyte viability and cardiac homeostasis.