Fatal Neonatal mTORopathy : Expanding the Phenotypic Spectrum of RRAGC ‐Associated L ong–

ABSTRACT

Dilated cardiomyopathy (DCM) is a severe cardiac condition characterized by the enlargement and impaired contraction of the heart's ventricles. Pediatric cases often present unique challenges due to their rarity and the complexity of underlying genetic causes. This study presents the first documented case of a Colombian patient with neonatal DCM, bilateral congenital cataracts, focal epilepsy, and hyperlactatemia. Genetic testing identified a pathogenic variant in the RRAGC gene, establishing the diagnosis of Long–Olsen–Distelmaier syndrome, a rare mTOR‐related disorder characterized by syndromic cardiomyopathy and multisystem involvement. Additionally, we review the clinical and molecular characteristics of previously reported cases in the literature.