Finally, the derived PRKAA1 SNP allele associated with heavier birth weight and larger uterine artery diameter was present at significantly higher frequency in Andeans than in Europeans (0.88 vs. 0.73, respectively), consistent with well-documented differences in altitude-associated IUGR and uteroplacental blood flow in women from these two groups (Wilson et al. Here, PRKAA1 is linked to fetal growth restriction.