Linkage between fetal A gamma globin chain polymorphism and DNA polymorphism of the human beta gene cluster in beta thalassaemia.
The association between the polymorphism of the A gamma chain of human fetal haemoglobin and the DNA polymorphism at the beta gene cluster has been investigated. The A gamma 75 threonine mutation was found in association with haplotypes II and VI described by Orkin et al. (1982), which share the HindIII cleavage site in the A gamma IVS 2 sequence. The distance between the two polymorphic sites is 868 base-pairs. In contrast, haplotypes I, III, V and IX which do not possess this HindIII cleavage site were associated with the normal A gamma 75 isoleucine allele. The simple detection of the gamma gene polymorphism at the protein level can be useful for identifying DNA haplotypes, and therefore beta thalassaemic mutations.
D002874:Chromosome Mapping; D004262:DNA Restriction Enzymes; D008040:Genetic Linkage; D005838:Genotype; D005914:Globins / Q000235:genetics*; D006801:Humans; D011110:Polymorphism, Genetic; D013789:Thalassemia / Q000235:genetics*
D005914:Globins; D004262:DNA Restriction Enzymes