Three brothers and two of their male first cousins were affected with a previously apparently undefined multiple congenital anomaly, mental retardation syndrome which was designated the FG syndrome and which consists of variable growth problems with a disproportionately large head, characteristic appearance and minor anomalies, imperforate anus, mild to severe mental retardation and congenital hypotonia; pyloric stenosis, hypoplastic left heart, generalized dilatation of the urinary tract, cutaneous syndactyly of third and fourth fingers, and severe craniosynostosis were seen each in 1 patient. Partial agenesis of the corpus callosum seen in 1 patient is suspected in another on the basis of EEG abnormalities. 1 boy died neonatally with congenital heart disease, and 2 others of pneumonia at 20 and 23 months. The FG syndrome is an X-linked recessive condition; heterozygotes appear grossly normal.
Multiple congenital anomaly/mental retardation (MCA/MR) syndrome Growth disturbances Increased headsize Hypotonia Imperforate anus Partial agenesis of corpus callosum Pyloric stenosis Generalized dilatation of urinary tract Hypoplastic left heart defect Syndactyly of toes and/or fingers Craniosynostosis X-linked inheritance