Prenatal diagnosis of trisomy 3 mosaicism

Constitutional and acquired autosomal aneuploidy

Chromosomal imbalances can result from numerical or structural anomalies. Numerical chromosomal abnormalities are often referred to as aneuploid conditions. This article focuses on the occurrence of constitutional and acquired autosomal aneuploidy in humans. Topics covered include frequency, mosaicism, phenotypic findings, and etiology. The article concludes with a consideration of anticipated advances that might allow for the development of screening tests and/or lead to improvements in our understanding and management of the role that aneuploidy plays in the aging process and acquisition of age-related and constitutional conditions.

Ultrasound manifestations of unusual trisomies-excluding trisomy 13, 18, and 21: a literature review

Trisomy is the most commonly identified chromosome abnormality, occurring in at least 4% of all clinically recognized pregnancies (1). Most of the trisomies are associated with a single additional chromosome, although 2 other types of trisomic conceptions are occasionally observed, those with 2 additional chromosomes or double trisomy and those with both a normal and trisomic cell line or mosaic trisomies. The adverse effects of trisomy on the phenotype are well established. In this review article, we consider the prevalence of the unusual trisomies (excluding 13, 18, and 21) and present a review of their ultrasound findings.