Question

Α-thalassemia with a cis deletion (cis or trans) is more prevalent in which population?

1) Asian populations
2) European populations
3) African populations
4) American populations

Answer 1

The cis deletion associated with α-thalassemia is most commonly found in Asian populations. This genetic condition affects hemoglobin synthesis and differs in prevalence among global populations, often influenced by regional diseases like malaria.

Step-by-step explanation:

α-thalassemia, a condition affecting the synthesis rate of the α-chain of globin, has differing prevalence in various populations. Specifically, the cis deletion of the gene associated with α-thalassemia is more commonly found in Asian populations. This condition can result in the formation of atypical hemoglobin molecules such as β4, β2δ2, or β2γ2 due to lack of the α chain. In contrast, β-thalassemia is characterized by the decreased synthesis rate of β-chain of globin, leading to the formation of different hemoglobin variants and severe anemia. Thalassemia itself is a genetic adaptation to malaria, prevalent in regions such as the Mediterranean, parts of Africa, and South and Southeast Asia. The sickle cell gene, often studied in relation to thalassemias, affects over 100 million people and is particularly prevalent among African descent populations, an adaptation also connected to malaria resistance. These genetic conditions illustrate how human genetics can be influenced by regional diseases and environmental pressures.