Bijanzadeh M, Rajaei Behbahani S.Arch Iran Med. 2020 May 1;23(5):356-358. doi: 10.34172/aim.2020.26.PMID: 32383621
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.