Honório Jonathan Celli, Bruns Rafael Frederico, Gründtner Luciana Fernandes, Raskin Salmo, Ferrari Lilian Pereira, Araujo Júnior Edward, Nardozza Luciano Marcondes Machado
Faculdades Integradas do Brasil UniBrasil, Curitiba, Paraná, Brazil.
Sao Paulo Med J. 2013;131(2):127-32. doi: 10.1590/s1516-31802013000100024.
Diastrophic dysplasia is a type of osteochondrodysplasia caused by homozygous mutation in the gene DTDST (diastrophic dysplasia sulfate transporter gene). Abnormalities occurring particularly in the skeletal and cartilaginous system are typical of the disease, which has an incidence of 1 in 100,000 live births.
The case of a pregnant woman, without any consanguineous relationship with her husband, whose fetus was diagnosed with skeletal dysplasia based on ultrasound findings and DNA tests, is described. An obstetric ultrasound scan produced in the 16th week of gestation revealed characteristics that guided the clinical diagnosis. Prominent among these characteristics were rhizomelia of the lower and upper limbs (shortening of the proximal portions) and mesomelia (shortening of the intermediate portions). Both upper limbs showed marked curvature, with the first finger of the upper limbs in abduction and clinodactyly of the fifth finger. Molecular analysis using the polymerase chain reaction (PCR) and gene sequencing detected mutations that had already been described in the literature for the gene DTDST, named c.862C > T and c.2147_2148insCT. Therefore, the fetus was a compound heterozygote, carrying two different mutations.
Prenatal diagnosis of this condition allowed a more realistic interpretation of the prognosis, and of the couple's reproductive future. This case report shows the contribution of molecular genetics towards the prenatal diagnosis, for which there are few descriptions in the literature.
脊柱骨骺发育不良是一种骨软骨发育不良，由DTDST基因（脊柱骨骺发育不良硫酸盐转运体基因）的纯合突变引起。该疾病的典型特征是骨骼和软骨系统出现异常，发病率为每10万例活产中有1例。
本文描述了一名孕妇的病例，她与丈夫无血缘关系，其胎儿经超声检查和DNA检测被诊断为骨骼发育不良。妊娠第16周的产科超声扫描显示出一些有助于临床诊断的特征。其中突出的特征是上下肢的短肢畸形（近端部分缩短）和中肢发育不全（中间部分缩短）。双上肢均有明显弯曲，上肢的食指外展，小指内弯。使用聚合酶链反应（PCR）和基因测序进行的分子分析检测到了文献中已描述的DTDST基因的突变，命名为c.862C>T和c.2147_2148insCT。因此，该胎儿是一个复合杂合子，携带两种不同的突变。
对这种情况进行产前诊断有助于更现实地解读预后以及这对夫妇的生育前景。本病例报告显示了分子遗传学在产前诊断中的作用，而关于这方面的文献描述较少。
