[Paternity study applying DNA polymorphism: evaluation of methods traditionally used in Chile]

Area of Science:

• Forensic Science
• Genetics
• Molecular Biology

Background:

• DNA fingerprinting (DNAfp) utilizes variable number tandem repeat (VNTR) loci for paternity identification.
• DNAfp allows for a higher rate of father exclusion compared to traditional erythrocyte antigen tests.
• The study investigates the comparative efficacy and optimal integration of DNAfp and antigen testing in paternity cases.

Purpose of the Study:

• To compare the effectiveness of DNA fingerprinting (DNAfp) with erythrocyte antigen tests in paternity identification.
• To evaluate the application of DNAfp in 34 paternity cases.
• To determine the most efficient and cost-effective approach for paternity testing.

Main Methods:

• DNA fingerprinting (DNAfp) was performed on 92 samples from 34 paternity cases using HaeIII-digested DNA.
• Results were compared with standard tests using ABO, Rh, MNSs, Duffy, and Kidd blood group systems.
• Analysis included band sharing between individuals and calculation of a posteriori probabilities.

Main Results:

• DNAfp generated an average of 14.07 bands (>4.3 Kb) per sample, with low band sharing (1.91%) between unrelated individuals.
• Two cases with high probability of paternity via antigen tests were clearly excluded by DNAfp.
• All exclusions made by antigen tests were confirmed by DNAfp; cases deemed 'rather probable' by DNAfp shared an average of 6.74 bands.

Conclusions:

• DNA fingerprinting (DNAfp) is a highly reliable method for paternity exclusion, surpassing traditional antigen tests.
• A sequential approach, starting with antigen testing followed by DNAfp for non-exclusions, is recommended for efficiency and cost savings.
• Increased exclusions through DNAfp contribute to overall economic benefits in paternity testing.