Which of the following is true about sickle cells?: (A) Sickling occurs equally in both heterozygous and homozygous variants, (B) Fetal hemoglobin facilitates sickling, (C) Sickling is reversible with oxygenation, (D) Sickling is associated with reduced MCHC
Answer is C. - Sickle cell disease is a common familial hemolytic anemia caused by a point mutation in b-globin in which glutamic acid is replaced by valine at 6th position. - It promotes the polymerization of deoxygenated hemoglobin, leading to red cell distoion, hemolytic anemia, microvascular obstruction, and ischemic tissue damage. - This sickling is reversible with oxygenation. - Sickling is severe in homozygous state than heterozygous state. - HbS facilitates sickling, not HbF - Dehydration & deoxygenation facilitates sickling