Prenatal diagnosis of partial trisomy 16p (16p12.2→pter) and partial monosomy 22q (22q13.31→qter) associated with increased nuchal translucency and abnormal maternal serum biochemistry in the first trimester

摘要

A 33-year-old, gravida 4, para 1, woman underwent first-trimester screening for chromosome abnormalities using ultrasound and maternal serum biochemistry at 13 weeks of gestation. The fetal nuchal translucency (NT) measured 3.62 mm (Fig. 1). The levels of free beta-human chorionic gonadotrophin (free (3-hCG) and pregnancy-associated plasma protein A (PAPP-A) were 0.686 multiples of median (MoM) and 0.272 MoM, respectively. The woman screened positive for trisomy 21 (risk of 1/11), trisomy 18 (risk of 1/33), and trisomy 13 (risk of 1/20). Chorionic villus sampling was performed. The fetal karyotype was 46,XX,der(22)t(16;22) (pl2.2;ql3.31) (Fig. 2). Cytogenetic analysis of the parents revealed a karyotype of 46,XY in the father and a karyotype of 46,XX,t(16;22)(pl2.2;ql3.31) in the mother (Fig. 3). The mother had experienced spontaneous abortions twice before and had a healthy 5-year-old son. The family did not had a history of congenital malformations. The woman had not b?en aware of her translocation status prior to this pregnancy.