Chaibunruang Attawut, Fucharoen Goonnapa, Fucharoen Supan
Biomedical Sciences Program, Graduate School, Khon Kaen University, Khon Kaen, Thailand.
Hemoglobin. 2012;36(1):80-4. doi: 10.3109/03630269.2011.599465. Epub 2011 Oct 3.
We report the molecular and hematological identifications of a Hb A(2) variant found for the first time in Thailand. The subjects were two unrelated Thai women who had normal hematological features. In the first case, hemoglobin (Hb) high performance liquid chromatography (HPLC) analysis identified, in addition to Hb A, Hb A(2) (1.6%) and a minor Hb variant (0.9%) separating after Hb A(2). Analysis using capillary electrophoresis (CE) demonstrated 1.3% Hb A(2) and 1.0% minor variant in zone 1. DNA analysis showed a single nucleotide mutation at codon 43 of the δ-globin gene (HBD:c.130G>A) causing a glutamic acid to lysine substitution corresponding to Hb A(2)-Melbourne, originally documented in an Italian subject, but not previously described in Thailand. The mutation could be confirmed by allele specific polymerase chain reaction (PCR) assay. Further screening using this technique in our series identified another case of a Thai woman with a double heterozygosity for Hb A(2)-Melbourne and α(+)-thalassemia (α(+)-thal). A β-globin gene haplotype associated with this Thai Hb A(2)-Melbourne gene was also established.
我们报告了在泰国首次发现的一种Hb A(2)变异体的分子和血液学鉴定结果。研究对象为两名血液学特征正常的泰国女性，她们彼此无关。在第一个病例中，血红蛋白（Hb）高效液相色谱（HPLC）分析显示，除了Hb A外，还有Hb A(2)（1.6%）和一个次要的Hb变异体（0.9%），该变异体在Hb A(2)之后分离出来。毛细管电泳（CE）分析显示，在区域1中有1.3%的Hb A(2)和1.0%的次要变异体。DNA分析显示，δ-珠蛋白基因（HBD:c.130G>A）的第43密码子处存在单核苷酸突变，导致谷氨酸被赖氨酸取代，这与最初在一名意大利受试者中记录的Hb A(2)-墨尔本变异体相对应，但此前在泰国尚未有过描述。该突变可通过等位基因特异性聚合酶链反应（PCR）检测得到证实。在我们的系列研究中，使用该技术进行进一步筛查，又发现了一例泰国女性，她同时为Hb A(2)-墨尔本变异体和α(+)-地中海贫血（α(+)-thal）的双重杂合子。还确定了与这种泰国Hb A(2)-墨尔本基因相关的β-珠蛋白基因单倍型。
