Occurrence of Hemoglobin G Cousha in Japan

Abstract

An abnormal hemoglobin with a substitution of Ala for Glu at the 22nd residue of the β chain has been found in North American Indians (Hbs G Coushatta and G Saskatoon) (1-3), Koreans (Hb G Taegu) (4-6) and Chinese (Hb G Hsin-Chu) (5,6). Blackwell et al (6) assumed that the Chinese and Korean subjects have the same hemoglobin variant because of gene flow. Surveys in the southwestern parts of Japan have uncovered two apparently unrelated families with this variant. This paper deals with the chemical and functional characterization of the Hb G Coushatta found in Japan.

The first family was discovered by agar gel electrophoresis at pH 8.6 (7) in 1971 during a survey of patients in Yamaguchi University Hospital. The patient, a 36-year-old female, had been admitted because of ruptured ectopic pregnancy. She had been healthy with no history of either anemia or jaundice. Routine hematology and blood chemistry twenty months later were normal. Her late father, who was assumed to have transmitted the gene for the variant hemoglobin, came to Japan from a village near Taegu, Korea and had many relatives in Taegu. Two of her three children carried the same variant, but all three were quite healthy. The variant hemoglobin comprised 33.4, 29.3 and 27.1 % of the total hemoglobin in the propositus and her two sons, respectively (determined by cellulose acetate membrane electrophoresis (8)). Results of Hb F (9), Hb A₂ (8), solubility (10), heat denaturation (11) and isopropanol (12) tests on the hemolysates were normal. the amino acid substitution in this hemoglobin has been reported (13).