Simpson-Golabi-Behmel (SGB) Syndrome Type 2 is a rare X-linked condition with macrosomia.
Chromosome: X
Location: Xp22 (SGB Type 1 maps to Xq26.2)
Genes affected: uncertain, possible CXORF5
Inheritance: X-linked
Clinical features:
(1) macrosomia
(2) hydrops fetalis
(3) macrocephaly
(4) craniofacial anomalies
(5) macroglossia
(6) jaundice
(7) brisk deep tendon reflexes and/or hypotonia
(8) seizures
(9) multiple congenital anomalies
(10) skeletal defects affecting limbs
Death occurs during infancy so there may not be time to develop malignant tumors.