Xxy and xyy: 47

47, XXY (Klinefelter syndrome) 47,XXX (Trisomy X) 47, XYY Trisomies are the most common X and Y aneuploid conditions. Less common are “tetrasomies,” which denote the presence of four sex chromosomes: 48,XXYY 48,XXXY 48,XXXX Still rarer are the “pentasomies,” indicating five sex chromosomes: 49,XXXXY 49,XXXXX However, for the psychological and behavioral symptoms of XXYY syndrome , more extensive evaluations, interventions, and supports are usually needed compared to 47, XXY due to more complex neurodevelopmental involvement. It was not until 1959 that these males were noted to have an extra X chromosome resulting in the karyotype of 47, XXY (Jacobs and Strong 1959). Although 47, XXY is the most common sex chromosomal condition, mosaic patterns (46,XY/47, XXY ) and additional X’s and/or Y such as 48,XXYY; 48,XXXY; and 47, XYY can occur although less frequently than 47, XXY . About 1:650–1,000 children are born with an extra X or Y chromosome (XXX; XXY ; XYY ), which results in a sex chromosome trisomy (SCT). This study aims to cross-sectionally investigate the impact of SCT on early social cognitive skills. Basic ...