Here, we present cases of structural Hb variants and thalassaemias which present either alone or together and reduce the level of HbA 2 at varying degrees. Furthermore, we present a novel structural mutation in the δ globin gene, called Hb A 2 -Madrid.

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.

In 65 (38%)/172 subjects with phenotypic α (+)-thalassemia trait, the mean HbA2 (2.43 ± 0.24%) was 0.13% lower than in subjects without α (+)-thalassemia trait, P < 0.0001. The mean HbA2 did not differ between males and females, smokers and nonsmokers, and between the tribes.

Iron deficiency modulates the synthesis of HbA2, resulting in reduced HbA2 levels in patients with iron deficiency anaemia. The diagnosis heterozygous beta-thalassaemia is based on a raised HbA2 level. Patients with beta-thalassaemia and concomitant iron …

2013年3月12日 · Since iron deficiency and α+ -thalassemia are both common and both lower HbA 2, modifications in screening recommendations for BTT are proposed. 1. Introduction. Screening for β -thalassemia trait (BTT) depends on measuring hemoglobin (Hb) A 2 accurately.

To address low levels of HbA2 specifically, it's crucial first to identify the underlying issue through comprehensive blood tests and possibly genetic testing. Once the cause is identified, a healthcare provider can recommend a treatment plan.

In addition, low levels of HbA2 (usually between 35% and 40%) are observed in delta thalassemia, delta/beta thalassemia, and some delta‐globin variants. Here, we report a Kurdish family with HBB mutation showing low level of HbA2 that passed the screening program and investigate the molecular basis of their condition.

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 (1.5%–3.1% of all hemoglobin molecules in adults) and is increased in people with SCD (http://www.ncbi.nlm.nih.gov/books/NBK1377/).

HbA 2 is usually raised in the beta thalassaemia (with a mild microcytic anaemia), and in unstable haemoglobinopathies where the amino acid substitution is on the beta chain.

Hemoglobin (Hb) A 2 (α 2 δ 2) constitutes less than 3% of the total hemoglobin (Hb) in adults and has almost no physiological importance. 1 On the other hand, the determination of Hb A 2 is an important tool to diagnose the beta-thalassemia trait (BTT). 1, 2 Although individuals with BTT do not need treatment, the accurate detection of the carri...