FG syndrome type 1

A rare X-linked syndromic intellectual disability characterized by developmental delay and intellectual disability, early hypotonia, constipation, feeding problems, imperforate anus, characteristic behavior (affable, eager to please), and dysmorphic craniofacial features (such as relative macrocephaly, prominent forehead with frontal hair upsweep, hypertelorism, downslanting palpebral fissures, and open mouth). Additional manifestations are partial agenesis of the corpus callosum, sensorineural hearing loss, joint laxity, cardiac anomalies, and abnormalities of the fingers and toes, among others.