Double trisomy 48,XXY,+21 in a neonate with congenital heart disease

Abstract

Double trisomy 48, XXY, +21 or Down-Klinefelter syndrome is a rare occurrence and presents clinical manifestation of trisomy 21 in early life and of Klinefelter syndrome after 10 months of age. The phenotypic and karyotyping characteristics of a 2-month-old boy were reported. He had mild clinical feature of Down syndrome and echocardiographic features of atrioventricular (AV) septal defects with severe pulmonary valve stenosis.