title: Prenatal diagnosis of the Dandy-Walker malformation and ventriculomegaly associated with partial trisomy 9p and distal 12p deletion.
abstract: OBJECTIVE
  To present the prenatal diagnosis and perinatal findings of partial trisomy 9p and distal 12p deletion.
  
  
  RESULTS
  Amniocentesis was performed at 17 gestational weeks due to a balanced reciprocal translocation t(9;12)(p11.2;p13.3) in the mother. The father's karyotype was normal. The family had a 5-year-old daughter with a Dandy-Walker malformation and a trisomy 9p syndrome. Cytogenetic analysis of the cultured amniotic fluid cells revealed a 46,XY,der(12)t(9;12)(p11.2;p13.3)mat karyotype with partial monosomy 12p(12pter-->p13.3) and partial trisomy 9p(9pter-->p11.2). Sonographic examination of the fetal brain and skull showed bilateral ventriculomegaly, brachycephaly and a Dandy-Walker malformation with an enlarged cisterna magna and absence of the cerebellar vermis. The pregnancy was terminated subsequently. At autopsy, the proband manifested agenesis of the cerebellar vermis and a typical trisomy 9p phenotype.
  
  
  CONCLUSIONS
  Fetuses with partial trisomy 9p(9pter-->p11.2) may present a Dandy-Walker malformation and ventriculomegaly on prenatal ultrasound in the second trimester. A dosage effect of genes located on 9pter-->p11.2 may be associated with the abnormal development of the central nervous system in patients with partial or complete trisomy 9.
authors.affiliation: Department of Obstetrics and Gynecology, Mackay Memorial Hospital, Taipei, Taiwan, Republic of China. cpc_mmh@yahoo.com
authors.forename: Chih-Ping
authors.initials: CP
authors.lastname: Chen
authors.forename: Tung-Yao
authors.initials: TY
authors.lastname: Chang
authors.forename: Jin-Chung
authors.initials: JC
authors.lastname: Shih
authors.forename: Shuan-Pei
authors.initials: SP
authors.lastname: Lin
authors.forename: Chen-Ju
authors.initials: CJ
authors.lastname: Lin
authors.forename: Wayseen
authors.initials: W
authors.lastname: Wang
authors.forename: Chen-Chi
authors.initials: CC
authors.lastname: Lee
authors.forename: Dai-Dyi
authors.initials: DD
authors.lastname: Town
authors.forename: Chen-Wen
authors.initials: CW
authors.lastname: Pan
authors.forename: Chin-Yuan
authors.initials: CY
authors.lastname: Tzen
mesh_terms: D000328:Adult; D000649:Amniocentesis; D001921:Brain / Q000002:abnormalities; D002478:Cells, Cultured; D002871:Chromosome Banding; D002872:Chromosome Deletion; D002881:Chromosomes, Human, Pair 12; D002899:Chromosomes, Human, Pair 9; D003616:Dandy-Walker Syndrome / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology; D005260:Female; D005865:Gestational Age; D006352:Heart Ventricles / Q000002:abnormalities* / Q000000981:diagnostic imaging; D006801:Humans; D011247:Pregnancy; D014314:Trisomy / Q000235:genetics* / Q000473:pathology; D016216:Ultrasonography, Prenatal