Hemoglobin Parchman: Double Crossover Within a Single Human Gene

Abstract
Structural analysis of a new variant hemoglobin revealed tryptic peptides with the amino acid composition of normal delta-globin, except for two internal peptides, which had the compositions of normal beta-globin. The most likely explanation for these findings is that a double, nonhomologous crossover between the delta-and beta-globin genes had occurred.