A Case Report of a Child With Rare Phosphatidylinositol Glycan Anchor Biosynthesis Class N (PIGN) Gene Mutation With Hypotonia, Epilepsy, and Global Developmental Delay

Phosphatidylinositol glycan anchor biosynthesis class N (PIGN) gene mutation is a rare autosomal recessive genetic disorder. PIGN is essential for the glycosylphosphatidylinositol (GPI) anchor biosynthesis pathway. These mutations are linked to multiple congenital anomalies-hypotonia-seizures syndrome 1 (MCAHS1). The affected PIGN gene leads to a significant reduction in the overall levels of GPI-anchored proteins and CD24 expression, suggesting that even partial depletion of these proteins can result in severe phenotypic manifestations. We present a case of a two-year-old boy diagnosed with spastic cerebral palsy following a hypoxic insult, who also exhibited refractory epilepsy, global developmental delay, and failure to thrive. Whole-exome sequencing confirmed a diagnosis of an autosomal recessive mutation in the PIGN gene. Given that mutations in the PIGN gene may be an underrecognized cause of epilepsy, this case report aims to highlight the importance of early diagnosis of this condition. Furthermore, our findings contribute to the expanding spectrum of PIGN gene mutations.