Molecular and Hematologic Analysis of Hemoglobin Q-Iran and Hemoglobin Setif in Iranian Families

Background: Single nucleotide mutations in α1 or α2 genes produce abnormal α-chain hemoglobins. Hemoglobin Q disorders including hemoglobin Q-Iran, hemoglobin Q-Thailand, and hemoglobin Q-India are important hemoglobin variants. Herein, we report on the presence and hematologic and molecular features of hemoglobin Q-Iran [α75 (EF4) Asp→His] in 20 members of 11 families including nine children and hemoglobin Setif [α94 (G1) Asp→Tyr] in 10 individuals from f ive families consisting of five children and their affected parents living in western Iran. Methods: A polymerase chain reaction-RFLP procedure using Ava II restriction enzyme was designed to confirm the presence of two α-chain variants. To find the coinheritance with α- thalassemia, the presence of deletions of -α3.7, -α20.5, --MED, --SEA, and nondeletion defects of IVSI (-5 bp) and hemoglobin CS was examined using polymerase chain reaction-based approaches. Results: The mean±SD level of hemoglobin Q-Iran was 20.4±4.4%. Three out of 18 individuals with hemoglobin Q-Iran were heterozygous for -α3.7 deletion (-α3.7/αα). The coinheritance of hemoglobin Q-Iran and -α3.7 deletion resulted in significantly (P=0.002) higher levels of hemoglobin Q-Iran (26.7±3.8 %). In those heterozygous for hemoglobin Setif, the level of this hemoglobin was 17.8±5.6 %. Conclusion: The polymerase chain reaction-RFLP method described here is a simple, rapid, and inexpensive procedure for the diagnosis of abnormal α-chains in developing countries.