Sizer Elaine B, Haw Tabitha, Wessels Tina-Marié, Kromberg Jennifer G R, Krause Amanda
Division of Human Genetics, School of Pathology, University of the Witwatersrand and the National Health Laboratory Services, Johannesburg, South Africa.
Genet Test Mol Biomarkers. 2012 Jan;16(1):58-62. doi: 10.1089/gtmb.2011.0007. Epub 2011 Aug 12.
Huntington disease (HD) is an autosomal dominant neurodegenerative disorder for which genetic counseling and testing are available in South Africa.
The purpose of this study was to assess the utilization of the services available in Johannesburg for diagnostic, predictive, and prenatal genetic testing and counseling for HD and the characteristics of the patients who use them.
A retrospective study was conducted using records of patients (n=287) who had genetic counseling and/or testing for HD through the Division of Human Genetics, National Health Laboratory Service and University of the Witwatersrand, Johannesburg, between January 1998 and December 2006. Age, gender, number of children, ethnicity, and test results were analyzed.
Of the 287 patients included in this study, 77% had diagnostic testing, 20% predictive, and 3% prenatal testing. In the diagnostic group, 47% of subjects tested positive for HD1 and 9% for HDL2 (all Black or of mixed ancestry). Altogether, 66.7% of subjects in the predictive group had testing and 39.5% were positive. In both groups, White subjects were overrepresented. In seven prenatal tests, three fetuses (including a set of twins) tested positive for HD and termination of pregnancy was requested.
The HD services for predictive and prenatal testing appear to be underutilized, especially by Black individuals, possibly because of lack of awareness among these individuals and among healthcare providers and/or a lower HD prevalence in this group. Recognition of and testing for HDL2 is important in South Africa's large Black population, and HD testing services cannot be considered complete unless testing for both HD1 and HDL2 are undertaken.
亨廷顿舞蹈症（HD）是一种常染色体显性神经退行性疾病，在南非可进行遗传咨询和检测。
本研究旨在评估约翰内斯堡提供的针对HD的诊断、预测和产前基因检测及咨询服务的利用情况，以及使用这些服务的患者的特征。
采用回顾性研究，分析了1998年1月至2006年12月期间通过约翰内斯堡国家卫生实验室服务部人类遗传学部门和威特沃特斯兰德大学进行HD遗传咨询和/或检测的患者（n = 287）的记录。分析了年龄、性别、子女数量、种族和检测结果。
本研究纳入的287例患者中，77%进行了诊断性检测，20%进行了预测性检测，3%进行了产前检测。在诊断组中，47%的受试者HD1检测呈阳性，9%的受试者HDL2检测呈阳性（均为黑人或混血）。在预测组中，共有66.7%的受试者进行了检测，39.5%呈阳性。在两组中，白人受试者占比过高。在七次产前检测中，三个胎儿（包括一对双胞胎）HD检测呈阳性，并被要求终止妊娠。
预测性和产前检测的HD服务似乎未得到充分利用，尤其是黑人个体，这可能是由于这些个体以及医疗服务提供者缺乏认识和/或该群体中HD患病率较低。在南非庞大的黑人人口中，识别和检测HDL2很重要，除非同时进行HD1和HDL2检测，否则不能认为HD检测服务是完整的。
