Intasai Nutjeera, Phasit Ampai, Panyasai Sitthichai, Pornprasert Sakorn
a Department of Medical Technology, Faculty of Associated Medical Sciences , Chiang Mai University , Chiang Mai , Thailand.
b Department of Medical Technology , Lampang Hospital , Lampang , Thailand.
Hemoglobin. 2019 Jan;43(1):63-65. doi: 10.1080/03630269.2019.1580587. Epub 2019 Apr 30.
Hb A' (or Hb B) (: c.49G>C) is the most frequent δ chain variant that has been described in Africa but not in Thailand. We report here a 10-month-old Thai infant with compound heterozygosity for β codon 17 (A>T; : c.52A>T) and β IVS II-654 (C>T; : c.316-197C>T). Under diagnosed β-thalassemia (β-thal) in her father, who carries Hb A' and a heterozygous β codon 17 mutation, and the mother, who carries a heterozygous β IVS II-654 mutation, was noted. Although Hb A' does not cause any problems, heterozygosity for Hb A' can lead to under diagnosis of β-thal in Hb A' samples. This case highlights the importance of Hb A' in prenatal diagnosis (PND). Thus, molecular analysis for β-thal mutations should be carried out when a small peak presents at the retention time (RT) of 4.71 min. on high performance liquid chromatography (HPLC) and the summation level of this peak and Hb A was equal or higher than 4.0%.
Hb A'（或Hb B）（：c.49G>C）是在非洲发现的最常见的δ链变异体，但在泰国尚未发现。我们在此报告一名10个月大的泰国婴儿，其为β密码子17（A>T；：c.52A>T）和β IVS II-654（C>T；：c.316-197C>T）的复合杂合子。在其父亲（携带Hb A'和杂合β密码子17突变）和母亲（携带杂合β IVS II-654突变）被诊断为β地中海贫血（β-地贫）的情况下，发现了该婴儿的情况。虽然Hb A'不会引起任何问题，但Hb A'的杂合性可能导致Hb A'样本中β-地贫的诊断不足。该病例突出了Hb A'在产前诊断（PND）中的重要性。因此，当在高效液相色谱（HPLC）上4.71分钟的保留时间（RT）出现一个小峰且该峰与Hb A的总和水平等于或高于4.0%时，应进行β-地贫突变的分子分析。
