Molecular and hematologic analysis of hemoglobin Q-Iran and hemoglobin Setif in Iranian families.

BACKGROUND Single nucleotide mutations in alpha1 or alpha2 genes produce abnormal alpha-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 [alpha75 (EF4) Asp-->His] in 20 members of 11 families including nine children and hemoglobin Setif [alpha94 (G1) Asp-->Tyr] in 10 individuals from five 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 alpha-chain variants. To find the coinheritance with alpha-thalassemia, the presence of deletions of -alpha3.7, -alpha20.5, --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 -alpha3.7 deletion (-alpha3.7/alpha alpha). The coinheritance of hemoglobin Q-Iran and -alpha3.7 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 alpha-chains in developing countries.