Mosaic trisomy 21 at amniocentesis associated with a favorable fetal outcome and perinatal progressive decrease of the trisomy 21 cell line

• Main Authors: Chih-Ping Chen (Author), Shin-Wen Chen (Author), Liang-Kai Wang (Author), Schu-Rern Chern (Author), Peih-Shan Wu (Author), Fang-Tzu Wu (Author), Yen-Ting Pan (Author), Chen-Chi Lee (Author), Li-Feng Chen (Author), Chen-Wen Pan (Author), Yun-Yi Chen (Author), Wayseen Wang (Author)
• Format: Book
• Published: Elsevier, 2023-01-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

Objective: We present mosaic trisomy 21 at amniocentesis associated with a favorable fetal outcome and perinatal progressive decrease of the trisomy 21 cell line. Case report: A 33-year-old woman underwent elective amniocentesis at 17 weeks of gestation because of anxiety, and the karyotype of cultured amniocytes was 47,XX,+21[4]/46,XX[13]. In 17 colonies of cultured amniocytes, four colonies had 47,XX,+21, while the other 13 colonies had 46,XX. Simultaneous array comparative genomic hybridization (aCGH) analysis on uncultured amniocytes revealed the result of arr (21) × 3 [0.32] consistent with 32% mosaicism for trisomy 21. Repeat amniocentesis performed at 25 weeks of gestation revealed 47,XX,+21[4]/46,XX[24] with four colonies of 47,XX,+21 and 24 colonies of 46, XX on cultured amniocytes, and arr 21q11.2q22.3 × 2.25 by aCGH, 19.2% mosaicism for trisomy 21 (20/104 cells) by interphase fluorescence in situ hybridization (FISH), and no uniparental disomy (UPD) 21 by quantitative fluorescence polymerase chain reaction (QF-PCR) on uncultured amniocytes. The parental karyotypes were normal, and prenatal ultrasound was unremarkable. A phenotypically normal 2815-g female baby was delivered at 38 weeks of gestation. Cytogenetic analysis on the cord blood, umbilical cord and placenta revealed the karyotype of 47,XX,+21[10]/46,XX[30]. 47,XX,+21[5]/46,XX[35] and 47,XX,+21[38]/46,XX[2], respectively. QF-PCR analysis on the DNA extracted from parental bloods, uncultured amniocytes, cord blood, umbilical cord and placenta confirmed a paternal origin of trisomy 21. When follow-up at age two months, the neonate was phenotypically normal, the peripheral blood had a karyotype of 47,XX,+21[6]/46,XX[34], and no trisomy 21 signals by interphase FISH was found on 100 buccal mucosal cells. When follow-up at age 13 months, the neonate was phenotypically normal, and the peripheral blood had a karyotype of 47,XX,+21[3]/46,XX[37]. Conclusion: Mosaic trisomy 21 at amniocentesis can be a transient and benign condition, and the abnormal trisomy 21 cell line may decrease and disappear after birth.

Item Description

1028-4559
10.1016/j.tjog.2022.01.011