Question

Β-thalassemia is usually due to gene mutations. These mutations affect the transcription, processing, or translation of beta-globin mRNA. Most commonly, they cause aberrant precursor mRNA splicing or premature chain termination during mRNA translation. In some cases, point mutations prevent RNA pol from binding to the promoter region. As opposed to alpha-thalassemia which is usually due to gene deletions. What is the main cause of β-thalassemia?

1) Gene deletions
2) Aberrant precursor mRNA splicing
3) Premature chain termination during mRNA translation
4) Point mutations preventing RNA pol from binding to the promoter region

Answer 1

The main cause of β-thalassemia is due to gene mutations leading to aberrant precursor mRNA splicing or premature chain termination during mRNA translation. These mutations decrease the synthesis rate of the beta-globin chain, causing an imbalanced hemoglobin and resulting in anemia.

Step-by-step explanation:

The main cause of β-thalassemia is typically due to gene mutations that affect the transcription, processing, or translation of beta-globin mRNA. These mutations most commonly result in aberrant precursor mRNA splicing or premature chain termination during mRNA translation, causing a decreased synthesis rate of β-chain of globin. This leads to an imbalance in the globin chains that make up hemoglobin, and as a consequence, ineffective erythropoiesis and anemia occur because the red blood cells have less hemoglobin and are less efficient at transporting oxygen.

While gene deletions are typically associated with alpha-thalassemia, β-thalassemia often arises from complex mutations including point mutations that might prevent RNA polymerase from binding to the promoter region, among other potential defects.