Article Title: A New Look at XXYY Syndrome: Medical and Psychological Features
Authors: Nicole Tartaglia, Shanlee Davis, Alison Hench, Sheela Nimishakavi, Renee Beauregard, Ann Reynolds, Laura Fenton, Lindsey Albrecht, Judith Ross, Jeannie Visootsak, Robin Hansen, and Randi Hagerman
Date of Publication: March 2008
“XXYY syndrome occurs in approximately 1:18,000–1:40,000 males. Although the physical phenotype is similar to 47,XXY (tall stature, hypergonadotropic hypogonadism, and infertility), XXYY is associated with additional medical problems and more significant neurodevelopmental and psychological features.”