Recent Advances in the Development of Methods for Detecting Single-base Substitutions Associated with Human Genetic Diseases

The ability to detect single-base mutations in human genomic DNA is of fundamental importance in the diagnosis of genetic diseases. This was first accomplished by using restriction endonucleases and the Southern blotting technique to detect the loss or gain of restriction enzyme recognition sites (Flavell et al. 1978; Geever et al. 1981). Unfortunately, this approach is limited by the fact that most single-base substitutions do not alter restriction endonuclease cleavage sites. In fact, sickle cell anemia is the only genetic disease that has been directly diagnosed by this method in the clinic on a routine basis (Chang and Kan 1982; Orkin et al. 1982). However, many genetic diseases can be diagnosed by this method by virtue of their linkage to restriction site polymorphisms (see, e.g., Kan and Dozy 1978; Gusella et al. 1982; Orkin et al. 1982). Base substitutions that do not alter restriction enzyme cleavage sites can be detected...