GPC3 and Simpson-Golabi-Behmel syndrome: Other potential candidate genes on the area are the skeletal muscle LIM protein 1, SLIM 1, which shows elevated expression levels in skeletal muscle during postnatal growth, and glypican 3, GPC3. Variants in GPC3 cause Simpson-Golabi-Behmel syndrome, a condition characterized by pre- and postnatal overgrowth (gigantism) with visceral and skeletal anomalies [32].