National Institute of Immunohaematology-ICMR, 13th Floor, New Multistoried Building, K.E.M. Hospital Campus, Parel, Mumbai‐400012, India.
Clin Chim Acta. 2012 Oct 9;413(19-20):1705-7. doi: 10.1016/j.cca.2012.05.019. Epub 2012 May 29.
An increased HbA2 level is the hallmark for identification of β thalassemia carriers. However, in some carriers the level of HbA2 is not typically elevated creating difficulties in making a diagnosis.
We describe a family having an affected child referred to us for confirmation of diagnosis of β thalassemia.
The father has a classical β thalassemia trait and the mother showed typical reduced red cell indices with a high RBC count but the HbA2 level was normal (2.4%). On molecular analysis she was a heterozygous carrier having IVS1 nt 5 (G→C) β thalassemia mutation. Further analysis of δ globin gene showed that the reduction in HbA2 was due to the presence of the δ mutation HbA2 Pelendri [CD 141(Leu→Pro, CTG→CCG)].
The diagnosis of a β thalassemia carrier could have been compromised, and states the importance of comprehensive molecular analysis for accurate diagnosis in couples where one partner has β thalassemia trait.
HbA2 水平升高是鉴定β地中海贫血携带者的标志。然而，在一些携带者中，HbA2 水平通常不会升高，这给诊断带来了困难。
我们描述了一个有受影响孩子的家庭，该孩子被转介给我们以确认β地中海贫血的诊断。
父亲患有典型的β地中海贫血特征，母亲表现出典型的红细胞指数减少，红细胞计数高，但 HbA2 水平正常（2.4%）。分子分析显示她是杂合子携带者，具有 IVS1 nt 5（G→C）β地中海贫血突变。δ珠蛋白基因的进一步分析表明，HbA2 的减少是由于存在 δ 突变 HbA2 Pelendri [CD 141（Leu→Pro，CTG→CCG）]。
如果伴侣一方患有β地中海贫血特征，那么对伴侣进行全面的分子分析对于准确诊断至关重要，否则β地中海贫血携带者的诊断可能会受到影响。
