Congenital or postnatal overgrowth syndrome most often in height and occipitofrontal circumference with variable delayed motor and cognitive development. Other associated features include advanced bone age, seizures, NEONATAL jaundice; HYPOTONIA; and scoliosis. It is also associated with increased risk of developing neoplasms in adulthood. Mutations in the NSD1 protein and its haploinsufficiency are associated with the syndrome.