节段分化不良，西尔弗曼-汉德马克型：双卵双胎妊娠中的一项具有挑战性的产前诊断。
Dyssegmental dysplasia, Silverman-Handmaker type: A challenging antenatal diagnosis in a dizygotic twin pregnancy.
作者信息
Basalom Shuaa, Trakadis Yannis, Shear Roberta, Azouz Michel E, De Bie Isabelle
机构信息
Department of Medical Genetics, McGill University Health Centre, Montréal, QC, Canada.
Department of Obstetrics and Gynecology, Jewish General Hospital, Montréal, QC, Canada.
出版信息
Mol Genet Genomic Med. 2018 May;6(3):452-456. doi: 10.1002/mgg3.379. Epub 2018 Mar 11.
BACKGROUND
Dyssegmental dysplasia Silverman-Handmaker (DDSH; MIM 224410) type is an extremely rare skeletal dysplasia caused by functional null mutations in the perlecan gene. Less than forty cases are reported in the literature, of which only four were prenatally detected.
METHODS
We report on a dizygotic twin pregnancy from consanguineous parents for which one of the twins presented prenatally with severe micromelia, limb bowing and scoliosis, and postnatally with clinical and radiological features compatible with a diagnosis of dyssegmental dysplasia. Molecular studies were undertaken to confirm the clinical diagnosis of DDSH.
RESULTS
Molecular analysis results revealed a novel homozygous variant in the HSPG2 gene (MIM 142461), NM_005529.6(HSPG2):c.4029 + 1G>A, consistent with a diagnosis of DDSH.
CONCLUSION
To the best of our knowledge, the current report is only the seventh molecularly confirmed case of DDSH.
背景
Silverman-Handmaker型节段分化不良（DDSH；MIM 224410）是一种极其罕见的骨骼发育不良，由基底膜聚糖基因的功能缺失突变引起。文献报道的病例不足40例，其中仅4例为产前诊断。
方法
我们报告了一对来自近亲父母的双卵双胎妊娠病例，其中一个胎儿产前表现为严重的短肢畸形、肢体弯曲和脊柱侧凸，出生后具有与节段分化不良诊断相符的临床和影像学特征。进行了分子研究以确诊DDSH的临床诊断。
结果
分子分析结果显示HSPG2基因（MIM 142461）存在一种新的纯合变异，NM_005529.6（HSPG2）：c.4029 + 1G>A，符合DDSH的诊断。
结论
据我们所知，本报告是DDSH分子确诊的第7例病例。
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