Tan J A, Tay J S, Lin L I, Kham S K, Chia J N, Chin T M, Aziz N B, Wong H B
Department of Paediatrics, National University of Singapore.
Prenat Diagn. 1994 Nov;14(11):1077-82. doi: 10.1002/pd.1970141112.
beta-Thalassaemia major patients have chronic anaemia and since 3-4 per cent of Singaporeans carry the beta-gene, prenatal diagnosis is essential. We evaluated the amplification refractory mutation system (ARMS) technique as a routine test for prenatal diagnosis of beta-major. Six mutations along the beta-gene were studied--41-42 (-TCTT), IVSII #654 (C-T), 17 beta (A-T), -28 TATA (A-G), IVSI #5 (G-C), and IVSI #1 (G-T). Our results indicate that prenatal diagnosis using these mutations can be offered to 90 per cent (35/39) of our Chinese couples and 54.6 per cent (12/22) of our Malay couples at risk. Confirmation of ARMS results was carried out using allele-specific oligonucleotide hybridization. Prenatal diagnosis using ARMS was successfully carried out in nine cases which included a set of triplets and twins. The triplets were diagnosed with the beta-trait carrying the 41-42 mutation. The couple with twins possessed the #654 mutation and one twin was diagnosed with the beta-trait and the other with #654 homozygosity. Genomic sequencing of the undefined mutations in the Chinese couples revealed rarer mutations at -29 and an ATG-AGG base substitution at the initiation codon for translation. In the Malay couples, genomic sequencing detected mutations at codon 15 (TGG-TAG) and codon 26 (GAG-AAG). We conclude that ARMS with its direct detection of amplified products by gel electrophoresis provides an accurate, rapid, and simpler method for our beta-thalassaemia prenatal diagnosis programme in Singapore.
重型β地中海贫血患者患有慢性贫血，由于3%至4%的新加坡人携带β基因，因此产前诊断至关重要。我们评估了扩增阻滞突变系统（ARMS）技术作为重型β地中海贫血产前诊断的常规检测方法。研究了β基因上的6种突变——41-42（-TCTT）、IVSII#654（C-T）、17β（A-T）、-28 TATA（A-G）、IVSI#5（G-C）和IVSI#1（G-T）。我们的结果表明，利用这些突变进行产前诊断，可为90%（35/39）有风险的华裔夫妇和54.6%（12/22）有风险的马来裔夫妇提供诊断。使用等位基因特异性寡核苷酸杂交对ARMS结果进行确认。利用ARMS成功进行了9例产前诊断，其中包括一组三胞胎和一对双胞胎。三胞胎被诊断为携带41-42突变的β性状。怀有双胞胎的夫妇携带#654突变，其中一个双胞胎被诊断为β性状，另一个为#654纯合子。对华裔夫妇中未明确的突变进行基因组测序，发现了-29处的罕见突变以及翻译起始密码子处的ATG-AGG碱基替换。在马来裔夫妇中，基因组测序检测到密码子15（TGG-TAG）和密码子26（GAG-AAG）处的突变。我们得出结论，通过凝胶电泳直接检测扩增产物的ARMS为我们新加坡的β地中海贫血产前诊断项目提供了一种准确、快速且更简单的方法。
