Double aneuploidy: 48, xxy,+ 18 in a bedouin boy

ABSTRACT

This study describes a case of double aneuploidy [48,XXY,+18], makes genotype-phenotype correlation of the case and compares it with those in the literature. This study throws more light on the origin of double aneuploidy. Clinical examination, skeletal survey, echocardiography, cranial ultrasonography and chromosomal examination of a peripheral blood sample using GTG-type of banding were performed. Clinical examination of the 25-day-old boy showed craniofacial dysmorphic features suggestive of trisomy 18, ventricular septal defect and complicated postnatal events leading to his neonatal death. Skeletal survey demonstrated absence of ossification centers of the epiphyses of long bones. Cranial ultrasonography revealed bilateral ventriculomegaly with thin cerebral cortex. Chromosomal analysis showed 48,XXY,+18 karyotype with no evidence of mosaicism. In the very few reported cases of double aneuploidy involving autosomes and sex chromosomes the clinical manifestations of the sex chromosome abnormality are usually missing. Double aneuploidy reflects a more serious segregation defect of meiosis than simple nondisjunction, and is not simply the result of the rare coincidence of paternal and maternal nondisjunction