A Novel Homozygous Missense Variant of PIGT Related to Multiple Congenital Anomalies-Hypotonia Seizures Syndrome 3 with Elevated of Serum ALP Level in a Thai Newborn Patient

Phosphatidylinositol glycan class T (PIGT) is part of the glycosylphosphatidylinositol transamidase (GPI-TA) complex, crucial for various cell functions. Biallelic pathogenic variants in PIGT are associated with Multiple Congenital Anomalies-Hypotonia Seizures Syndrome 3 (MCAHS3), a rare neonatal hypotonia syndrome characterized by dysmorphic features and seizures. Diagnosing neonatal hypotonia, which has diverse congenital and acquired causes, is challenging, particularly in syndromic monogenic cases. Next-generation sequencing is essential for accurate diagnosis. This study reports a term newborn with hypotonia, dysmorphic features, seizures, and severe skeletal issues, including a humeral fracture at birth, consistent with MCAHS3.