Hi I am 18 an just got tested for huntington's disease. Can someone please explain what (allele 1: w/ 31 cag and allele 2: w/ 15 cag repeats means?

Talk with doc. You really should speak with the person who ordered the test to get the final interpretation. In general, huntington's disease (hd) is caused by an expansion of cag repeats. The range of repeat length in the unaffected population is 6–35 repeats. We have two copies, or alleles, of the gene. Both of your alleles are in the normal range, thus no hd. Once again, speak with your doc for final word.