Can a dna test not be conclusive because of mutated genes?

Question

my father and girl A took a test and this is what he told me.i didn,t see the results,could this be true?an honest answer would be appeciated,thanks

Answer 1

If you are talking about a DNA paternity test (whether this child and this adult are related), no, mutations would have no affect on the outcome of the results.  This is mainly because several different alleles are examined, and it is virtually impossible to acquire mutations that would affect each one.  In fact, all of us are genetically different because of random mutations, and if this did have an affect, we would not be able to use DNA for anything.

Answer 2

Perhaps that is a two-part question.  If the mutated gene existed in the sperm or egg being fertilized, offspring will have an exact copy of the mutation within every cell and a DNA test should be conclusive.  If a mutation occurs in a few or even many cells in an adult (etc.) likely other unchanged cells will be tested for DNA.  Also, mitochrondia have their own unique DNA (passed on by a mother's egg but not by a sperm) and that should not be affected by mutation of a cell's genes.