Identification of the Molecular Genetic Defect of Patients With Methemoglobin M Kankakee (M-Iwate), α87 (F8) His → Tyr: Evidence for an Electrostatic Model of αM Hemoglobin Assembly

We determined that the molecular defect of 2 patients with hemoglobin (Hb) M-Kankakee [Hb M-Iwate, α87 (F8) His → Tyr] resides in the α1-globin gene. The proportion of Hb M observed is higher than that predicted for an α1-globin variant. Our evidence suggests that the greater-than-expected proportion of Hb M-Kankakee results from preferential association of the electronegative β-globin chains with the αM-globin chains that are more electropositive than normal α-globin chains.