Intrauterine growth: association with acid phosphatase genetic polymorphism.

Acid phosphatase (ACP1) is an enzyme found in the cytoplasm of many tissues and probably functions as a flavin mononucleotide-phosphatase. Therefore the highest concentration of flavin-mononucleotide cofactors is expected in ACP1 phenotypes with the lowest enzymatic activity (A and BA) and the lowest concentration of these cofactors is expected in phenotypes with the highest activity (CB and C). Accordingly, metabolic activities related to flavoenzymes should attain maximal levels in A and BA phenotypes and minimal levels in CB and C phenotypes. In the present study we have analyzed possible effects of ACP1 genetic variability on intrauterine growth in a sample of 609 newborns collected from three consecutive series in Rome. An association between ACP1 and birth weight is observed. The association is present only among male infants. ACP1 phenotypes with low enzymatic activity (A and BA) show a clear tendency to higher rates of intrauterine growth. A linear negative correlation is also observed between enzymatic activity and quartile class. The relation is significant only in male infants. The data suggest that in fetuses with low ACP1 activity, metabolic activity may be regulated at a level allowing a full response to specific genetic stimuli maximizing fetal growth.