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.

HbA2, composing of two α chains and two δ chains, is a minor component of the hemoglobin present in normal adult red blood cells, accounting for about 2.5% of the total hemoglobin in healthy individuals. However, HbA2 level is also elevated in some pregnant women.

2018年1月25日 · In particular, the percentage of hemoglobin (Hb) A 2 is elevated, while the red cell mean corpuscular volume (MCV) and/or mean corpuscular hemoglobin (MCH) are decreased. The red blood cell count is usually normal or increased, but may be decreased if the patient has other causes of anemia.

Hemoglobin (Hb) A2' is a hematologically silent variant of HbA2 that is detected easily by high-performance liquid chromatography (HPLC), where it elutes in the S window.

2023年5月1日 · Beta-thalassemia refers to an inherited mutation of the beta-globin gene, causing a reduced beta-globin chain of hemoglobin. The highest prevalence of beta-thalassemia mutations is in people of Mediterranean, Middle Eastern, and Asian descent.

What does it mean if your Hemoglobin A2 (Quant) result is too high? Elevated levels of Hemoglobin A2 (HbA2) in a blood test can indicate certain health conditions, most notably beta thalassemia, a blood disorder. Hemoglobin is a protein in your red blood cells that carries oxygen throughout your body.

A: The normal Hb A2 level in an adult is less than 3.5% and it is elevated (>4%) in b-thalassaemia trait. Your Hb A2 value lies in the indeterminate range. Beta thalassaemia trait (or...

2024年7月23日 · In clinical practice, the critical factor for detecting β-thalassemia trait is high hemoglobin A2 (HbA2) levels (≥3.5%) on high-performance liquid chromatography (HPLC) after a suspicion finding during complete blood cell count (CBC) assessment. 2 Changes in erythrocyte parameters on CBC have been studied extensively and even automated using art...

In Sicily, there is a high heterogeneity of molecular defects and a prevalence of mutations causing β + - or β ++ -thalassemia, 2,6 so that a reliable HbA 2 assessment is essential for accurate diagnosis and genetic counseling.

Hb A (α 2 β 2) is the major Hb component of normal humans after the age of 1-year old, composing more than 96% of total Hb, followed by 2.5-3.5% of Hb A 2 (α 2 δ 2) and less than 1.0% of Hb F (α 2 γ 2). An increased Hb A 2 level to more than 3.5% has been used as a marker of a β-thalassemia carrier.