Mosaic trisomy 22 at amniocentesis: Prenatal diagnosis and literature review

Taiwan J Obstet Gynecol. 2019 Sep;58(5):692-697. doi: 10.1016/j.tjog.2019.07.020.

Abstract

Objective: We present prenatal diagnosis of mosaic trisomy 22 at amniocentesis in a pregnancy with facial cleft, oligohydramnios and intrauterine growth restriction (IUGR), and we review the literature.

Case report: A 37-year-old woman underwent amniocentesis at 19 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 47,XX,+22[9]/46,XX[9]. Array comparative genomic hybridization (aCGH) analysis on uncultured amniocytes showed a result of arr(22) × 3 [0.8]. Prenatal ultrasound revealed fetal median facial cleft, oligohydramnios and IUGR. Repeat amniocentesis at 22 weeks of gestation using uncultured amniocytes revealed an aCGH result of arr 22q11.1q13.33 (17,397,498-51,178,264) × 2.8 compatible with 80% mosaicism for trisomy 22, and a fluorescence in situ hybridization (FISH) result of mosaic trisomy 22 with trisomy 22 in 54/100 interphase cells. The cultured amniocytes at repeat amniocentesis had a karyotype of 47,XX,+22[12]/46,XX[8]. The parental karyotypes were normal. Polymorphic DNA marker analysis confirmed a maternal origin of the extra chromosome 22. The pregnancy was terminated, and a 256-g female fetus was delivered with facial dysmorphism and median facial cleft. Cytogenetic analysis of the skin fibroblasts revealed a karyotype of 47,XX,+22[33]/46,XX[7].

Conclusion: Fetuses with high level mosaicism for trisomy 22 at amniocentesis may present IUGR, facial cleft and oligohydramnios on prenatal ultrasound.

Keywords: Amniocentesis; Mosaic trisomy 22; Prenatal diagnosis; Ultrasound.

Publication types

  • Case Reports
  • Review

MeSH terms

  • Abortion, Induced
  • Adult
  • Amniocentesis / methods*
  • Chromosome Disorders / diagnosis*
  • Chromosome Disorders / embryology
  • Chromosomes, Human, Pair 22
  • Comparative Genomic Hybridization
  • Female
  • Fetal Growth Retardation / diagnosis*
  • Fetal Growth Retardation / genetics
  • Humans
  • In Situ Hybridization, Fluorescence
  • Maxillofacial Abnormalities / diagnosis*
  • Maxillofacial Abnormalities / embryology
  • Maxillofacial Abnormalities / genetics
  • Mosaicism / embryology
  • Oligohydramnios / diagnosis*
  • Oligohydramnios / genetics
  • Pregnancy
  • Trisomy / diagnosis*
  • Ultrasonography, Prenatal
  • Uniparental Disomy / diagnosis*

Supplementary concepts

  • Trisomy 22 mosaicism syndrome