n. an overgrowth-related disorder which stems from a problem with insulin growth factor 2. In line with gene encoding, this traces back to the short arm (11p15) of chromosome 11. Usually congenital, the five birth defects noted include neonatal hypoglycemia (low sugar), macroglossia (enlarged tongue), macrosomia (increased birth size & weight), abdominal hernia, and ear creases or pits. These may also be accompanied by mental retadation in some cases. First observed by German pediatrician Hans Rudolf Weidermann (1915- ) and U.S, physician Bruce Beckwith (1933- ).