Adenylate kinase locus 1 polymorphism and feto-placental development

Objective Recently our group has found that the correlation between birth weight and placental weight – an index of a balanced feto-placental unit development – is influenced by genetic factors. Since adenylate kinase locus 1 (AK 1 ) is a polymorphic enzyme that plays an important role in the synthesis of nucleotides required for many metabolic functions, we have investigated the possible role of its genetic variability in the correlation between birth weight and placental weight. Study design 342 consecutive healthy newborn infants from the population of Rome (Italy) and 286 puerperae from another population from Central Italy were studied. Results The correlation coefficient between birth weight and placental weight is much higher in infants with low activity AK 1 2-1 phenotype than in those with high activity AK 1 1 phenotype. The difference between AK 1 and AK 1 2-1 is well marked only in newborns with a gestational age greater than 38 weeks and it is not influenced by sex, maternal age and maternal smoking. A similar pattern is observed with maternal AK 1 phenotype. Conclusions These results suggest that the difference in enzymatic activity between AK 1 phenotypes influencing the equilibrium among ATP, ADP, AMP and adenosine could have an important role in a balanced development of feto-placental unit.