PATERNITY STUDIES APPLYING DNA POLYMORPHI SM - COMPARISON WITH THE METHODS IN USE IN CHILE

Simultaneous detection of several VNTR loci using a single DNA probe i s the basis of the technique called ''DNA fingerprint'' (DNAfp) of inc reasing application in parenthood identification. According to the dat a gathered by different laboratories worldwide, father exclusion can b e made in a larger number of cases when compared with the customary te sts based on erythrocyte antigens. The question could then be whether DNAfp will completely replace erythrocyte antigens tests. We report he re our experience in applying DNAfp to 92 samples corresponding to 34 paternity cases and comparing these with the results obtained with the antigens of the systems ABO, Rb, MNSs, Duffy and Kidd. Most of the Ha eIII/digested DNA samples produced 13 to 16 bands larger than 4,3 Kb ( average 14,0761 +/- 2,205). Average band sharing between pairs of unre lated individual was 1.9107 +/- 1,083. Two cases presenting on a poste riori probability of being the father of 80.7% and 76.5% by erythrocyt e antigens were clearly excluded by DNAfp. All exclusions made by anti gens were confirmed by DNAfp. In the cases reported as father ''rather probable'' (28 cases) by DNAfp, these shared with the child 6.707 +/- 1,7 bands on average. Because of time, cost and simplicity we favor a procedure starting with the antigens test and continuing with DNAfp o nly when an exclusion is not possible. Economy will increase as the nu mber of exclusions increases.