WBCS Preliminary Examination 2023 — General Studies · Question 196 of 200

Answer: (B) Thalassemia

Thalassemia is an autosomal recessive disorder: the defective globin genes lie on chromosome 16 (alpha) or chromosome 11 (beta), not on the sex chromosomes, so both sexes are equally affected. Haemophilia and red–green colour blindness are sex-linked (X-linked recessive) disorders, far more common in males, with females usually acting as carriers. Other autosomal disorders are sickle-cell anaemia, phenylketonuria and cystic fibrosis. Chromosomal disorders are a separate group: Down syndrome (trisomy 21), Turner syndrome (XO) and Klinefelter syndrome (XXY). World Thalassemia Day is 8 May.