Mathijssen Inge B, Henneman Lidewij, van Eeten-Nijman Janneke M C, Lakeman Phillis, Ottenheim Cecile P E, Redeker Egbert J W, Ottenhof Winnie, Meijers-Heijboer Hanne, van Maarle Merel C
Department of Clinical Genetics, Academic Medical Center, Amsterdam, The Netherlands.
Department of Clinical Genetics, VU University Medical Center, Amsterdam, The Netherlands.
Eur J Med Genet. 2015 Mar;58(3):123-8. doi: 10.1016/j.ejmg.2015.01.004. Epub 2015 Jan 30.
In a genetically isolated community in the Netherlands four severe recessive genetic disorders occur at relatively high frequency (pontocerebellar hypoplasia type 2 (PCH2), fetal akinesia deformation sequence (FADS), rhizomelic chondrodysplasia punctata type 1 (RCDP1), and osteogenesis imperfecta (OI) type IIB/III. Over the past decades multiple patients with these disorders have been identified. This warranted the start of a preconception outpatient clinic, in 2012, aimed at couples planning a pregnancy. The aim of our study was to evaluate the offer of targeted genetic carrier screening as a method to identify high-risk couples for having affected offspring in this high-risk subpopulation. In one year, 203 individuals (92 couples and 19 individuals) were counseled. In total, 65 of 196 (33.2%) tested individuals were carriers of at least one disease, five (7.7%) of them being carriers of two diseases. Carrier frequencies of PCH2, FADS, RCDP1, and OI were 14.3%, 11.2%, 6.1%, and 4.1% respectively. In individuals with a positive family history for one of the diseases, the carrier frequency was 57.8%; for those with a negative family history this was 25.8%. Four PCH2 carrier-couples were identified. Thus, targeted (preconception) carrier screening in this genetically isolated population in which a high prevalence of specific disorders occurs detects a high number of carriers, and is likely to be more effective compared to cascade genetic testing. Our findings and set-up can be seen as a model for carrier screening in other high-risk subpopulations and contributes to the discussion about the way carrier screening can be offered and organized in the general population.
在荷兰一个基因隔离的社区中,四种严重的隐性遗传疾病以相对较高的频率出现(2型脑桥小脑发育不全(PCH2)、胎儿运动不能变形序列(FADS)、1型肢根型点状软骨发育不良(RCDP1)和IIB/III型成骨不全(OI))。在过去几十年中,已确诊多名患有这些疾病的患者。这促使在2012年开设了一家孕前门诊,面向计划怀孕的夫妇。我们研究的目的是评估靶向基因携带者筛查作为一种方法,用于识别这个高危亚人群中生育患病后代的高危夫妇。在一年时间里,为203人(92对夫妇和19名单身个体)提供了咨询服务。在196名接受检测的个体中,共有65人(33.2%)是至少一种疾病的携带者,其中5人(7.7%)是两种疾病的携带者。PCH2、FADS、RCDP1和OI的携带者频率分别为14.3%、11.2%、6.1%和4.1%。对于有其中一种疾病家族史阳性的个体,携带者频率为57.8%;对于家族史阴性的个体,这一频率为25.8%。确定了四对PCH2携带者夫妇。因此,在这个特定疾病高发的基因隔离人群中进行靶向(孕前)携带者筛查,能检测出大量携带者,并且与级联基因检测相比可能更有效。我们的研究结果和模式可被视为其他高危亚人群中携带者筛查的典范,并有助于推动关于在普通人群中如何提供和组织携带者筛查的讨论。