Gene analysis of hemoglobin M-Hyde Park [β92His → Tyr] *
Hemoglobin（Hb）M-Hyde Park［b92His→Tyr］is a type of Hb M diseases in which the cyanosis and hemolytic anemia are caused by ferri-Hb formation due to amino acid replacement of the b-globin chain. In the present study, the author examined the hemoglobinopathy of a Pakistani family, which is composed of the propositus（one year old boy suspected of Hb M disease）, his parents and an elder brother. It was decided that two members of the family, the boy and his father, were heterozygous for Hb M-Hyde Park. Single nucleotide polymorphism（SNP）at the seven positions of the b globin gene cluster（haplotype）and five SNPs of the b-globin gene（framework）of this family and three Japanese families（six patients）were determined by PCR-RFLP and PCR-direct sequencing. The results showed that the SNPs of the abnormal allele obtained from the six Japanese carriers of Hb M-Hyde Park were of only one type, but that of the Pakistani family were different from those of the Japanese. Therefore, it was deduced that origins of Hb M-Hyde Park differ in the Pakistani and Japanese. In addition, the Single Step Extension Method（SSEM;or SNaPshot method）for gene analysis was applied to determine the framework of the b-globin gene. The results were consistent with that of PCR-direct sequencing. This SSEM might be considered to be simpler and better than the ARMS（Amplification Refractory Mutation System）, PCR-RFLP（Polymerase Chain Reaction-Restriction Fragment Length Polymorphism）and SSCP（Single Strand Conformation Polymorphism）methods for the detection of known mutations or SNPs. (Accepted on October 21，2004)
