Polymorphism of DNA sequence adjacent to human beta-globin structural gene: relationship to sickle mutation.

TLDR

Polymorphisms in restriction enzyme sites represent a novel class of genetic markers that could aid linkage analysis and anthropological studies. Mapping of the human beta‑globin locus uncovered a polymorphic Hpa I site 5 kb from the gene’s 3′ end, producing 7.0‑kb and 13.0‑kb fragments that occur only in people of African ancestry and that the 13.0‑kb variant is frequently linked to the sickle‑cell mutation, making it a potential prenatal diagnostic marker.

Abstract

Restriction endonuclease mapping of the human globin genes revealed a genetic variation in a Hpa I recognition site about 5000 nucleotides from the 3' end of the beta-globin structural gene. Instead of a normal 7.6-kilobase (kb) fragment which contains the beta-globin structural gene, 7.0-kb and 13.0-kb variants were detected. Both variants were found in people of African origin and were not detected in Asians or Caucasians. The 13.0-kb variant is frequently associated with the sickle hemoglobin mutation and may be useful for the prediction of the sickle cell gene in prenatal diagnosis. Polymorphism in a restriction enzyme site could be considered as a new class of genetic marker and may offer a new approach to linkage analysis and anthropological studies.