47,XYY Karyotypes and Pervasive Developmental Disorders

Abstract

Objective: The presence of a 47,XYY karyotype in boys with pervasive developmental disorders (PDDs) has rarely been described in the past. Herein, 2 boys with PDDs and a supernumerary Y chromosome are presented. Methods: The case histories of the 2 patients are described along with the results of associated testing. The literature on psychosocial development as well as brain morphology and physiology in males with 47,XYY karyotypes is reviewed. Results: Both boys had presentations typical of PDDs, one with autistic disorder and the other with PDD not otherwise specified. Conclusions: The finding that, in a clinic for children with developmental disorders, 2 of 40 male referrals had 47,XYY karyotypes suggests that the rate of this sex chromosome anomaly may be increased in PDDs. An extra Y chromosome may be related to abnormal brain development, which may, in turn, predispose vulnerable males to PDDs.