The unprecedented recurrent diploid/tetraploid mosaicism of trisomy-18 (mixoploidy; 4n+18/2n+18): clinical report

Am J Med Genet A. 2015 Jul;167(7):1650-3. doi: 10.1002/ajmg.a.37062. Epub 2015 Apr 6.

Abstract

We report on a 32-year-old woman who presented at gestational age of 14 weeks. During ultrasonographic examination, we discovered that her fetus had several important abnormalities, including a cystic hygroma, craniofacial defects (low-set ears, broad nose), heart defects (single atrium, single ventricle), agenesis of corpus callosum, limb defects (clenched hands, pes equinovarus). Chorionic villus sampling and karyotyping revealed diploid/tetraploid mosaicism with trisomy 18 (mixoploidy; 4n+18/2n+18). Her second pregnancy was terminated because of the same clinical manifestations 1 year prior. Her first pregnancy resulted in the birth of an entirely healthy boy. As far as know, no other similar case has been presented in the literature.

Keywords: recurrent diploid/tetraploid mosaicism; trisomy 18.

Publication types

  • Case Reports

MeSH terms

  • Abnormalities, Multiple / genetics*
  • Abnormalities, Multiple / pathology*
  • Chromosomes, Human, Pair 18 / genetics
  • Female
  • Fetus*
  • Heart / physiopathology
  • Humans
  • Karyotyping
  • Male
  • Pedigree
  • Ploidies*
  • Pregnancy
  • Trisomy / genetics*
  • Trisomy / pathology*
  • Trisomy 18 Syndrome
  • Ultrasonography, Prenatal