title: Complete trisomy 9 with unusual phenotypic associations: Dandy-Walker malformation, cleft lip and cleft palate, cardiovascular abnormalities.
abstract: OBJECTIVE
  Trisomy 9 is a rare chromosomal abnormality usually associated with first-trimester miscarriage; few fetuses survive until the second trimester. We report two new cases of complete trisomy 9 that both present unusual phenotypic associations, and we analyze the genetic pathway involved in this chromosomal abnormality.
  
  
  METHODS
  The first fetus investigated showed Dandy-Walker malformation, cleft lip, and cleft palate) at the second trimester scan. Cardiovascular abnormalities were characterized by a right-sided, U-shaped aortic arch associated with a ventricular septal defect (VSD). Symmetrical intrauterine growth restriction and multicystic dysplastic kidney disease were associated findings. The second fetus showed a dysmorphic face, bilateral cleft lip, hypoplastic corpus callosum, and a Dandy-Walker malformation. Postmortem examination revealed cardiovascular abnormalities such as persistent left superior vena cava draining into the coronary sinus, membranous ventricular septal defect, overriding aorta, pulmonary valve with two cusps and three sinuses, and the origin of the left subclavian artery distal to the junction of ductus arteriosus and aortic arch.
  
  
  CONCLUSIONS
  Complete trisomy 9 may result in a wide spectrum of congenital abnormalities, and the presented case series contributes further details on the phenotype of this rare aneuploidy.
authors.affiliation: Department of Obstetrics and Gynecology, Prenatal Diagnostic Service, Guastalla Civil Hospital, Azienda Unità Sanitaria Locale Reggio Emilia, Reggio Emilia, Italy. Electronic address: tonnig@ausl.re.it.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Tonni
authors.affiliation: Preconceptional and Prenatal Diagnostic Center, Istituto di Ricerca a Carettere Clinico Scientifico Galliera Hospital, Genoa, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Lituania
authors.affiliation: Department of Obstetrics and Gynecology, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Chitayat
authors.affiliation: Pathology Service, Istituto di Ricerca a Carettere Clinico Scientifico Arcispedale Santa Maria Nuova, Reggio Emilia, Italy.
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Bonasoni
authors.affiliation: Department of Laboratory Medicine and Pathology, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Keating
authors.affiliation: Department of Laboratory Medicine and Pathology, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Megan
authors.initials: M
authors.lastname: Thompson
authors.affiliation: Department of Laboratory Medicine and Pathology, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: Patrick
authors.initials: P
authors.lastname: Shannon
mesh_terms: D000015:Abnormalities, Multiple / Q000175:diagnosis / Q000235:genetics*; D000025:Abortion, Eugenic; D000328:Adult; D018376:Cardiovascular Abnormalities / Q000175:diagnosis / Q000235:genetics*; D002899:Chromosomes, Human, Pair 9; D002971:Cleft Lip / Q000175:diagnosis / Q000235:genetics*; D002972:Cleft Palate / Q000175:diagnosis / Q000235:genetics*; D003616:Dandy-Walker Syndrome / Q000175:diagnosis / Q000235:genetics*; D005260:Female; D006801:Humans; D010641:Phenotype; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011296:Prenatal Diagnosis; D014314:Trisomy
keywords: Dandy-Walker malformation; aneuploidy; congenital abnormalities; congenital heart disease; right aortic arch; trisomy 9