Explain thalassemia.

(N/A) Thalassemia is an autosomal recessive blood disorder characterized by abnormal hemoglobin production.
$1$. It is caused by mutations in the genes that code for the globin chains of hemoglobin.
$2$. The disorder is classified into two main types: $\alpha$-thalassemia and $\beta$-thalassemia.
$3$. In $\alpha$-thalassemia,the production of the $\alpha$-globin chain is affected,which is controlled by two closely linked genes,$HBA1$ and $HBA2$,on chromosome $16$.
$4$. In $\beta$-thalassemia,the production of the $\beta$-globin chain is affected,which is controlled by a single gene,$HBB$,on chromosome $11$.
$5$. The condition leads to the formation of abnormal hemoglobin molecules,resulting in the destruction of red blood cells (anemia).