title: Dyssegmental dysplasia, Silverman-Handmaker type: prenatal ultrasound findings and molecular analysis.
abstract: OBJECTIVE
  The objective of this study is to describe the prenatal sonographic features and the results of DNA analysis on three fetuses with dyssegmental dysplasia, Silverman-Handmaker type (DD-SH).
  
  
  METHODS
  A retrospective review of three fetuses with confirmed DD-SH was conducted. The fetal ultrasound findings, the radiological characteristics, and the results of the mutation analysis of the heparan sulphate perlecan gene 2 (HSPG2) were reviewed.
  
  
  RESULTS
  There were three cases in two families with DD-SH diagnosed prenatally. The main prenatal ultrasound and the radiological features of DD-SH were severe limb shortening and vertebral segmentation and fusion defects (anisospondyly). The DNA analysis of the HSPG2 gene showed that the two affected fetuses in a nonconsanguineous family had a compound heterozygote for the c.646G > T transversion in exon 7 and a c.5788C > T transition in exon 46. The fetus born to the consanguineous couple had a homozygous mutation c.1356-27_1507 + 59del.
  
  
  CONCLUSIONS
  DD-SH can be diagnosed prenatally using fetal ultrasound as early as 13 weeks. Xrays and DNA analysis of the HSPG2 gene are important for the confirmation of the diagnosis and for the preimplantation and prenatal diagnosis in pregnancies at risk.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynaecology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Canada.
authors.forename: Noor Niyar N
authors.initials: NN
authors.lastname: Ladhani
authors.forename: David
authors.initials: D
authors.lastname: Chitayat
authors.forename: Marjan M
authors.initials: MM
authors.lastname: Nezarati
authors.forename: Mittaz Crettol
authors.initials: MC
authors.lastname: Laureane
authors.forename: Sarah
authors.initials: S
authors.lastname: Keating
authors.forename: Rachel J
authors.initials: RJ
authors.lastname: Silver
authors.forename: Sheila
authors.initials: S
authors.lastname: Unger
authors.forename: Lea
authors.initials: L
authors.lastname: Velsher
authors.forename: Wilma
authors.initials: W
authors.lastname: Sirkin
authors.forename: Ants
authors.initials: A
authors.lastname: Toi
authors.forename: Phyllis
authors.initials: P
authors.lastname: Glanc
mesh_terms: D000025:Abortion, Eugenic; D000328:Adult; D004392:Dwarfism / Q000000981:diagnostic imaging* / Q000235:genetics*; D005260:Female; D006801:Humans; D025202:Molecular Diagnostic Techniques; D011247:Pregnancy; D012189:Retrospective Studies; D050497:Stillbirth; D016216:Ultrasonography, Prenatal; D055815:Young Adult