Rs17602729

This position is odd. Under the older reference genome build36, it was on the plus strand; in build37 it is on the minus strand. This makes it very prone to some ambiguous flip confusion in the literature, plus, 23andMe users have self-reported the flipped form. IN addition, instead of the usual SNP listed as having 2 alleles, all 4 alleles are reported in dbSNP, even if this is probably due to the strand changes. dbSNP currently says the normal allele is C, and T is the rare geno which causes a premature stop, early in the gene. We at SNPedia suspect that the A & G alleles are not common enough to have ever been genuinely reported, but for de-novo mutations each allele would be non-synonymous and result in a different amino acid. http://snpedia.blogspot.com/2012/12/snpedias-nightmare-before-christmas.html

rs17602729, a SNP located in the AMPD1 gene and also known as 'C34T', has at times been called the "most prevalent genetic disease mutation", at least in Caucasians. Perhaps up to 10% of Caucasians and African-American carry one C34T allele (i.e. carry one rs17602729(A) allele) - and actually, most of them are unaware of any medically related issues since they don't typically have any particular symptoms that would warrant a trip to the doctor.

So what's the issue? The AMPD1 gene encodes the enzyme adenosine monophosphate deaminase, which is one of the key enzymes used to process the energy source ATP. The C34T variation causes a premature stop in the protein, leading to a nonfunctional AMPD1 enzyme. Some individuals - but by no means all or even a majority apparently - who are AMPD1 deficient get muscle cramps and pains when they exert themselves. The most common genotype bringing this about is rs17602729(A;A), i.e. the individuals who carry two copies of the C34T allele and therefore have no functioning AMPD1 allele. It is not known why only some of C34T homozygotes experience muscle myalgia.

Heterozygotes, i.e. rs17602729(A;G) individuals, do not seem to suffer any exercise or fitness related deficit. In fact, one of the best elite Caucasian distance runners is known to be a C34T heterozygote.

In fact, heterozygotes for rs17602729 may even have advantages over those lacking a C34T allele. The most striking study reported that C34T heterozygotes are 8.6 fold (CI: 3.05 - 23.87) more likely to survive for more than 5 years without needing a heart transplant after a congestive heart failure related hospitalization than the wild-type homozygotes (i.e. rs17602729(G;G) homozygotes). Similarly, C34T heterozygotes with coronary artery disease seem to fare better than wild-type homozygotes.

This is one of the SNPs reported by NutraHacker.