Screening for causative genes in unknown hemolytic anemia

α-血红蛋白稳定蛋白（AHSP）与α-血红蛋白特异性结合，并阻止其在红细胞（RBC）中的沉淀。AHSP作为分子伴侣，稳定不稳定的游离α-珠蛋白单体，产生活性氧，对红细胞蛋白和脂质造成损伤。为了研究AHSP基因缺陷可能导致Heinz体阳性贫血或感染或药物引起的急性溶血性贫血，我们通过检测28例溶血性贫血患者和95例对照者的7个snp（单核苷酸多态性）进行了一项病例对照研究，发现人类AHSP基因的某一单倍型与未知溶血性贫血亚群有显著关联。该单倍型在AHSP基因5'侧包含4个snp （-557G、-465T、-201G和+248A）和1个缺失插入多态性（DIP） T15，报告基因分析表明，该单倍型的转录活性约占对照单倍型的23%。体外诱变分析显示SNP-201G和T15都是导致AHSP基因转录活性降低的原因。我们得出结论，AHSP基因与亨氏体红细胞阳性或感染/药物引起的溶血性贫血的疾病易感性相关，并且201a /T15的纯合子更容易受到氧化应激的影响。

Alpha-hemoglobin stabilizing protein (AHSP) binds specifically to α-hemoglobin, and prevents its precipitation in red blood cells (RBC). AHSP plays an important role as a molecular chaperone in the stabilization of unstable free α-globin monomer, which generates reactive oxygen species, resulting in damage to red cell protein and lipids. To examine that AHSP gene defects might account for either Heinz body-positive anemia or acute hemolytic anemia triggered by infection or drug administration, we performed a case-control study by examining seven SNPs (single nucleotide polymorphisms) of 28 hemolytic anemia patients and 95 controls, and found that a certain haplotype of the human AHSP gene had significant association with a subgroup of unknown hemolytic anemia. The haplotype included four SNPs (-557G,-465T,-201G and +248A) and a deletion-insertion polymorphism (DIP), T15, in 5'-flanking region of AHSP gene, and a reporter gene assay showed that the haplotype accounts for about 23% transcriptional activity of a control haplotype. In vitro mutagenesis analysis revealed that both the SNP-201G and T15 are responsible for decreased transcriptional activity of AHSP gene. We conclude that the AHSP gene is correlated to disease-susceptibility in a group of hemolytic anemia with either Heinz body-positive RBC or infection/drug-induced episodes, and that the homozygotes of-201A/T15 are more susceptible to oxidative stress.