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Thalassaemia is
Autosomal recessive disease
Autosomal dominant disease
Sex-linked dominant disease
Sex-linked recessive disease
Solution
Thalassaemia
$(i)$ It is an autosome-linked recessive disesase
$(ii)$ It occurs due to either mutation or deletion resulting in reduced rate of synthesis of one of globin chains of haemoglobin
$(iii)$ Anaemia is the characteristic of this disease
$(iv)$ Thalassaemia is classified into two types
$1.$ $\alpha$ – thalassaemia Production of $\alpha$-globin chain is affected. It is controlled by the closely linked genes $HBA1$ and $HBA2$ on chromosome $16.$ It occurs due to mutation or deletion of one or more of the four genes.
$2.$ $\beta$-thalassaemia Production of $\beta$-globin chain is affected. It occurs due to mutation of one or both $HBB$ genes on chromosome $11$