Badyal Rama Kumari, Chhabra Sanjeev, Sharma Prashant, Das Reena
Department of Haematology, Postgraduate Institute of Medical Education and Research , Chandigarh , India.
Hemoglobin. 2014;38(6):440-3. doi: 10.3109/03630269.2014.976413. Epub 2014 Oct 29.
Cation exchange high performance liquid chromatography (HPLC) is commonly utilized as the first method of screening for thalassemias and hemoglobinopathies worldwide. This method of diagnosis requires knowledge of the clinical background and complete blood counts as well as skill and experience in interpreting the sometimes complex results produced. An asymptomatic 27-year-old pregnant North Indian woman was found to have a highly unusual chromatographic pattern with multiple unexpected peaks during routine antenatal screening. Most concerning was a C-window peak as Hb C (HBB: c.19G>A) is rare in ethnic Asian Indian populations. Cellulose acetate electrophoresis at alkaline pH (8.6) and parental screening were performed. These revealed the correct diagnosis to be a double heterozygosity for Hb Q-India (HBA1: c.193G>C) (an uncommon asymptomatic α-globin chain variant) plus Hb D-Punjab (HBB: c.364G>C) (a β-globin chain variant that is common in this region and is asymptomatic in the heterozygous state). The unexpected C-window peak was the hybrid of the abnormal α-Q-India and β-D-Punjab globin chains. Another small peak was explained as a variant Hb A2 formed by the combination of α-Q-India and δ-globin chains. Hematopathologists should be cognizant of the complex pattern resulting from coinheritance of both α- and β-globin structural variants. Second-line testing and parental testing are invaluable in resolving unknown peaks, especially if rare or unexpected variants are being considered. Although both Hb Q-India and Hb D-Punjab are relatively common in northwestern India, to the best of our knowledge, only two recent reports describe a total of three cases of such diagnostically puzzling coinheritance.
阳离子交换高效液相色谱法（HPLC）是全球范围内用于地中海贫血和血红蛋白病筛查的首选方法。这种诊断方法需要了解临床背景和全血细胞计数，以及解读有时复杂的检测结果的技能和经验。一名无症状的27岁北印度裔孕妇在常规产前筛查中被发现具有高度异常的色谱图，出现多个意外峰。最令人担忧的是出现了一个C窗峰，因为Hb C（HBB：c.19G>A）在亚洲印度裔人群中很罕见。进行了碱性pH值（8.6）下的醋酸纤维素电泳和双亲筛查。结果显示正确诊断为Hb Q-印度（HBA1：c.193G>C）（一种不常见的无症状α-珠蛋白链变体）和Hb D-旁遮普（HBB：c.364G>C）（一种β-珠蛋白链变体，在该地区很常见，杂合状态下无症状）的双重杂合子。意外的C窗峰是异常的α-Q-印度和β-D-旁遮普珠蛋白链的杂交产物。另一个小峰被解释为由α-Q-印度和δ-珠蛋白链组合形成的变体Hb A2。血液病理学家应认识到α-和β-珠蛋白结构变体共同遗传所产生的复杂模式。二线检测和双亲检测对于解决未知峰非常重要，特别是在考虑罕见或意外变体时。尽管Hb Q-印度和Hb D-旁遮普在印度西北部相对常见，但据我们所知，最近仅有两篇报告总共描述了三例这种诊断令人困惑的共同遗传病例。
