A 47, XXY patient and Xq21.31 duplication with features of Prader-Willi syndrome: results of array-based comparative genomic hybridization.

A man diagnosed with 47, XXY during childhood presents an appearance similar to that of Prader-Willi syndrome with hypogonadism and gynecomastia, developmental delay, and short stature and obesity. Array-based comparative genomic hybridization revealed duplication at Xq21.31 in addition to his abnormal karyotype. This duplication was also found in his mother who appeared normal. We raise the possibility that the phenotype in this patient is a combination of both extra X chromosome and Xq21 duplication.