Search for retroviral related DNA polymorphisms using RAPD PCR in schizophrenia

Random amplification of polymorphic DNA (RAPD) is widely used to detect pol ymorphisms in many organisms. Individual (or strain) specific amplified ban ds are generated with single or pairs of primers in PCR reactions and can s erve as genetic markers. We have used this method to generate a large numbe r of reproducible bands with single primers, random and retroviral related, on 92 human DNA samples. Theoretically, RAPD PCR presents a logical approa ch for assessing variability among individuals. We used ten retroviral rela ted primers (12, 20 and 22 bp) and eight random primers (10 bp) to assess i ndividual differences in the context of testing the retroviral hypothesis f or schizophrenia. Three pairs of discordant monozygotic twins, four pairs o f discordant full sibs and 53 schizophrenic individuals with 25 of their un related matched controls were analyzed. Ten of these primers resulted in a total of approx. 850 amplified bands (65 110 bands per primer). Almost all of these bands were identical among each individual analyzed. However, the results are inconclusive with respect to the retroviral hypothesis for schi zophrenia. The general lack of RAPD polymorphism in this study may argue fo r mechanisms other than rearrangements such as inversions, associated with the evolution of the human genome. (C) 1999 Elsevier Science B.V. All right s reserved.