Which of the following genetic disorders is characterized by an autosomal recessive inheritance pattern resulting in abnormal sickle-shaped hemoglobin molecules under low oxygen tension?

💡 Solution & Explanation

Sickle cell anemia is caused by a point mutation in the beta-globin gene on chromosome 11, substituting valine for glutamic acid, which alters hemoglobin solubility and causes red blood cells to deform into rigid sickle shapes under low oxygen conditions. Phenylketonuria is an amino acid metabolism disorder, Down syndrome involves trisomy 21, and Hemophilia A is an X-linked recessive bleeding disorder. Heterozygous carriers exhibit resistance against severe malaria infection.