Sickle Hemoglobin in Combination With Hb JBangkok (αA2β56 gly→asp2)

Abstract

Abstract Several members of a black family from Southern Illinois were found to be heterozygous for HB JBangkok (αA2β56 gly→asp2), a hemoglobin abnormality previously described only in individuals of Thai, Chinese, or Indonesian ancestry. In two children (ages 3 and 8) Hb JBangkok was present in combination with sickle hemoglobin. Neither of these children demonstrated evidence of hemolytic disease, enlargement of the liver or spleen, or symptomatic sickle crises. The Hb J comprised 54%-59% of the total in all family members having this variant, in common with previous reports of this hemoglobin. Hb A2 and alkali-resistant hemoglobin were present in normal concentrations in all of the family members studied. Deoxygenated mixtures of Hbs S and JBangkok exhibited minimum gelation concentrations similar to those of equivalent mixtures of Hbs S and A.