Hemoglobin H disease is caused by deletion: (A) Single a globin chain, (B) Two a globin chains, (C) Three a globin chains, (D) All a globin chain
Answer is C. Ans. (c) Three a globin chains(Ref: Robbins 9th/pg 638)Classification of a-thalassemia:Normally 4 a-genes synthesize: 2 a chains -> a, a / a, aMost common cause of a -thalassemia is a -gene deletion (frame-shift mutation)9