RFLPs in Mapping Genetic Diseases

hemoglobin gene from each family member

Hb A is the wild type allele, and Hb S is the allele that codes for the sickling of red blood cells

RFLP's are produced using this polymorphic DNA sequence and the resulting fragments are separated by gel electrophoresis

The wild-type hemoglobin gene, Hb A, appears at 1.15 kb, while the sickled hemoglobin gene, Hb S, appears at 1.35 kb.

A person homozygous for sickle cell anemia (S/S) shows only one RFLP at 1.35 kb, while people heterozygous for this disease (A/S) have RFLP's at 1.35 kb and 1.15 kb.

People who have not inherited this gene (A/A) show one RFLP at 1.15 kb.