Sickle Hemoglobin in Combination With Hb J^Bangkok (α^A₂β^{56 gly→asp}₂)

Several members of a black family from Southern Illinois were found to be heterozygous for HB J^Bangkok (α^A₂β^{56 gly→asp}₂), a hemoglobin abnormality previously described only in individuals of Thai, Chinese, or Indonesian ancestry. In two children (ages 3 and 8) Hb J^Bangkok 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 J^Bangkok exhibited minimum gelation concentrations similar to those of equivalent mixtures of Hbs S and A.