Hemoglobin A2 (HbA2) is a normal variant of hemoglobin A that consists of two alpha and two delta chains (α 2 δ 2) and is found at low levels in normal human blood. Hemoglobin A2 may be increased in beta thalassemia or in people who are heterozygous for the beta thalassemia gene.

2025年2月1日 · Measurement of hemoglobin A 2 is an important parameter for beta thalassemia diagnosis and carrier screening [3], [4]. In noncarriers, HbA 2 values are typically between 2 and 3 %, while in carriers they are generally above 4 %.

两条 α 链加上两条 β 链构成 HbA，在正常成人生活中约占总血红蛋白的 97%； alpha 链与 delta 链结合构成 HbA-2，它与 HbF (胎儿血红蛋白) 一起构成成人血红蛋白的剩余 3%。 α 地中海贫血是由每个 α 基因的缺失以及 HBA2 和 HBA1 的缺失引起的；一些非缺失性 α 地中海贫血也有报道。 [RefSeq 提供，2008 年 7 月]

Quantitative HbA2 determination is the most valuable test for β-thalassaemia carrier identification. Several methods have been set up, but only a few are now recommended for their accuracy. It should be pointed out that the precision and accuracy of HbA2 determination using densitometry scanning after cellulose acetate electrophoresis is ...

HbA2' is a clinically silent hemoglobinopathy that results from modification of δ globin gene (GGC → CGC) substituting glycine for arginine at codon 16 [3]. This genetic disorder has been detected in homozygous [7] and heterozygous states [8], and may also be co-inherited with HbS [9], β-thalassaemia traits [10] and other minor hemoglobinopathies.

本专题将讨论α珠蛋白基因(hba1和hba2)检测结果的意义。这些基因的致病性变异(常为缺失)可导致α地中海贫血。 α珠蛋白基因检测不能识别β地中海贫血或其他累及β珠蛋白的疾病，如镰状细胞病。

The establishment of reference systems for the standardization of hemoglobin A 2 (HbA 2) and fetal hemoglobin (HbF), both critical for improving diagnostic accuracy in conditions such as β-thalassemia and sickle cell disease, are described.

2024年12月25日 · HBA2 (Hemoglobin Subunit Alpha 2) is a Protein Coding gene. Diseases associated with HBA2 include Hemoglobin H Disease and Alpha-Thalassemia. Among its related pathways are Erythrocytes take up carbon dioxide and release oxygen and …

正常成人红细胞中有三种血红蛋白即HbA、 HbA2 和 HbF。 HbA（a2b2）是正常成人红细胞中的最主要的血红蛋白，占红细胞内血红蛋白总量的96%以上，PI=6.7。 HbA2(a2d2) 是正常成人红细胞中的次要成分，占2~3% 左右，其PI>6.7。

两个α链加上两个β链构成HbA，在正常成年生活中约占总血红蛋白的97%；α链与δ链结合构成HbA-2，与HbF（胎儿血红蛋白）一起构成成年血红蛋白的剩余3%。 α地中海贫血是由每个α基因的缺失以及HBA2和HBA1的缺失引起的；已经报道了某些非缺失的α地中海贫血。 [由RefSeq，2008年7月提供] Dir./Indir. The sequence and analysis of duplication-rich human chromosome 16. Hemoglobin J Cape Town-alpha-2 92 arginine replaced by glutamine beta-2.