an uncommon chromosomal disorder wherein a male is genetically predisposed to and given three extra X chromosomes resulting in a multitude of abnormalities, inclusive of unusually small genitalia, a small, wide neck, and hypotonia. Most impacted people have cognitive retardation, with IQ's less than 60.

XXXXY SYNDROME: "Males with XXXXY syndrome usually have small, thick necks. "
Cite this page: N., Pam M.S., "XXXXY SYNDROME," in, April 29, 2013, (accessed September 28, 2021).