title: Mosaic trisomy 16 in a fetus: the complex relationship between phenotype and genetic mechanisms.
abstract: OBJECTIVE
  This study was undertaken to discuss the workup of trisomy 16 pregnancies.
  
  
  METHODS
  This case study reports the prenatal detection and postnatal confirmation of mosaic trisomy 16, associated with uniparental disomy (UPD) 16, in a 34-year-old woman who showed elevated maternal serum alpha-fetoprotein and beta-HCG at a gestational age (GA) of 15.5 weeks.
  
  
  RESULTS
  Amniotic fluid (AF) karyotyping at different GAs revealed various levels of trisomy 16 mosaicism (0 to level III). UPD studies at 21 weeks of gestation revealed maternal heterodisomy 16. Serial fetal ultrasonography showed fetal abnormalities: intrauterine growth restriction (IUGR), dilated digestive tract, and gallbladder agenesis. Postmortem examination confirmed the prenatal findings and revealed additional anomalies, such as hypoplastic cerebellum with abnormal gyration of the vermis.
  
  
  CONCLUSIONS
  Workup following prenatal detection of trisomy 16 mosaicism in chorionic villi must include AF karyotyping and serial ultrasound examination of the fetus in order to approach postnatal developmental prognosis.
authors.affiliation: Department of Medical Genetics, Chu Montpellier, France.
authors.forename: Kamran
authors.initials: K
authors.lastname: Moradkhani
authors.forename: Jacques
authors.initials: J
authors.lastname: Puechberty
authors.forename: Patricia
authors.initials: P
authors.lastname: Blanchet
authors.forename: Christine
authors.initials: C
authors.lastname: Coubes
authors.forename: Hakima
authors.initials: H
authors.lastname: Lallaoui
authors.forename: Patricia
authors.initials: P
authors.lastname: Lewin
authors.forename: Genevieve
authors.initials: G
authors.lastname: Lefort
authors.forename: Pierre
authors.initials: P
authors.lastname: Sarda
mesh_terms: D000028:Abortion, Induced; D000328:Adult; D000649:Amniocentesis; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000097:blood; D025063:Chromosome Disorders / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000235:genetics*; D002885:Chromosomes, Human, Pair 16; D005260:Female; D005315:Fetal Diseases / Q000175:diagnosis / Q000235:genetics; D005317:Fetal Growth Retardation / Q000235:genetics; D006801:Humans; D007621:Karyotyping; D008297:Male; D009030:Mosaicism; D010641:Phenotype; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods; D014314:Trisomy; D014463:Ultrasonography; D000509:alpha-Fetoproteins / Q000032:analysis
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D000509:alpha-Fetoproteins