Evaluation of random cDNA clones as probes for human restriction fragment polymorphisms

The purpose of this study was to evaluate the usefulness of randomly isolated human cDNA clones as probes for human restriction fragment polymorphisms. Clones were chosen from two human cDNA libraries and tested by hybridization against Southern blots of genomic DNA prepared from nine individuals. Three types of hybridization patterns were seen with the individual clones tested, those representative of single copy genes, others representative of gene families, and one characteristic of a mitochondrial gene. Only two of these cDNA clones revealed any polymorphisms among the individuals tested: pDK-08 and RW12, both representative of gene families. Both revealed independent polymorphisms with several of the restriction enzymes tested, and inheritance of these polymorphisms as Mendelian alleles was verified by human pedigree analysis. The results are discussed with regard to the usefulness of such cDNA clones in revealing polymorphisms in human genetic analysis.