Hemoglobin Kenya composed of α‐ and (Aγβ)‐fusion‐globin chains, associated with hereditary persistence of fetal hemoglobin

Hb Kenya is made up of two normal alpha-globin chains and two (A)gammabeta-fusion globin chains. The latter are the product of an (A)gammabeta-hybrid globin gene formed as a result of misalignment during meiosis and nonhomologous crossing over. It is associated with a deletion of 22.7 kb including the delta-globin gene, between the (A)gamma- and beta-globin genes. Hb Kenya is found in Kenyans and Ugandans. Heterozygotes have moderately increased Hb F, and this mutation has been known as an ((A)gammabeta)(+) hereditary persistence of fetal hemoglobin (HPFH). Compound heterozygotes for Hb Kenya/Hb S are thought to be asymptomatic, but reports of long term follow-up of these patients are lacking. The correct identification of Hb Kenya is sometimes problematic. In cation exchange high performance liquid chromatography, Hb Kenya elutes in similar position as Hb A(2), Hb Lepore, Hb E, and several other variant hemoglobins. Definitive diagnosis that is necessary for proper patient management is best done by DNA-based gap-PCR tests.