title: Mosaic double aneuploidy: Down syndrome and XYY.
abstract: Chromosomal abnormalities are seen in nearly 1% of live born infants. We report a 5-year-old boy with the clinical features of Down syndrome, which is the most common human aneuploidy. Cytogenetic analysis showed a mosaicism for a double aneuploidy, Down syndrome and XYY. The karyotype was 47, XY,+21[19]/48, XYY,+21[6]. ish XYY (DXZ1 × 1, DYZ1 × 2). Mosaic double aneuploidies are very rare and features of only one of the aneuploidies may predominate in childhood. Cytogenetic analysis is recommended even if the typical features of a recognized aneuploidy are present so that any associated abnormality may be detected. This will enable early intervention to provide the adequate supportive care and management.
authors: Cytogenetics Unit, Christian Medical College, Vellore, Tamil Nadu, India.
authors: Mayur
authors: M
authors: Parihar
authors: Beena
authors: B
authors: Koshy
authors: Vivi Miriam
authors: VM
authors: Srivastava
keywords: Disorder of sexual development; Down syndrome with XYY; double aneuploidy; meiotic non-disjunction; mosaic