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Background: We have searched for a possible association of the genetic polymorphism of Phosphoglucomutase locus 1 (PGM1), a key enzyme in carbohydrate metabolism, with body mass., Methods: Adults (n = 257) with type 2 diabetes, 74 children referred for "obesity," and 740 consecutive healthy newborn infants were studied. Body mass index, body weight, birth weight, and PGM1 phenotype were determined. Sexes were analyzed separately., Results: In type 2 diabetes, females carrying the PGM1*2 allele are less represented among subjects with extreme body mass index deviation as compared with other classes of subjects. Among children referred for "obesity," females carrying the PGM1*2 allele are less represented among children with extreme body weight deviation. Among consecutive infants, in both sexes the proportion of those showing a birth weight higher than the 3rd quartile is lower in homozygous PGM12/2 subjects than in other PGM1 phenotypes., Conclusions: The data suggest that during extrauterine life, females carrying the PGM1*2 allele are relatively protected from extreme body mass increase. During intrauterine life, PGM12/2 homozygotes show a tendency to low body mass increase. Because PGM1 enzymatic activity depends on its phosphorylation status by the kinase Pak1, both structural differences of the PGM1 allelic product and different rates of activation by Pak between sexes might be responsible for the pattern observed. At present, the effect of other genes near PGM1 and in linkage disequilibrium with it cannot be ruled out.

Experimental data and clinical observations suggest that delaying childbearing influences the biology of the mother-fetus relationship, with a negative effect on fetal development and predisposition to severe diseases such as type 1 diabetes. We reason that advanced maternal age may influence intrauterine selection, favoring genotypes that are more adapted to the intrauterine environment of less young women. In the present study we have investigated the relationship of maternal age to HP genotype and PGM1-Rh area (chromosome 1) that have been previously found to be associated with fertility and developmental parameters. HP phenotype was determined in 679 consecutive puerperae from the population of central Italy. PGM1 phenotype and Rh C phenotype were determined in 222 puerperae and 200 newborns. The HP 1,1 phenotype decreases and the HP 2,2 phenotype increases with maternal age. The proportion of phenotypes carrying both the Rh C and PGM1*1 alleles is much higher in puerperae older than 36 years than in puerperae of age 22 years. The frequency of the PGM1*1-Rh C haplotype increases and the frequency of the PGM1*2-Rh C haplotype decreases with maternal age. The changes in these genetic systems with advancing maternal age are similar in mothers and newborns. The delay of childbearing age, associated in Western countries with the fertility transition in addition to detrimental effects on intrauterine development and increased susceptibility to severe disorders, could bring about changes in the genetic composition of a population.

A deviation of the maternal-neonatal joint phosphoglucomutase locus 1 (PGM1) distribution from Hardy-Weinberg expectation has been reported. It was suggested that selection on PGM1 during intrauterine life might account for these deviations and that maternal and paternal PGM1 alleles might have different associations with intrauterine survival. This study considered possible associations between the joint mother-newborn PGM1 genotype and intrauterine growth. There was a significant association between birth weight percentile class and mother-newborn PGM1 genotype in infant females. Also, the paternal PGM1*2 allele was associated negatively with macrosomia, and this effect was significant only in female infants.

Genetic polymorphism subtypes of PGM1 and GC were studied in four samples of the Sardinian population from the four Provinces of the island. The results show heterogeneity within the Sardinian population. The PGM1 alleles exhibiting the greatest variability were: PGM1*1S and PGM1*1F, with a range of .675-.724 (Nuoro - Sassari) and .072-.107 (Sassari - Nuoro) respectively. The observed GC allele frequency range were: GC*1F = .029-.168 (Cagliari - Sassari); GC*1S = .565-.752 (Sassari - Oristano); GC*2 = .194-.267 (Cagliari - Sassari). Sardinians showed a marked differentiation with respect to other Italian and European populations thus confirming their genetic peculiarity.

Esterase D (ESD), glyoxalase 1 (GLO1), phosphogluconate dehydrogenase (PGD) and phosphoglucomutase 1 and 2 (PGM1 and PGM2) systems have been studied in the Salerno province (Campania, Southern Italy). The mean weighted frequencies for the Campania region were calculated. These frequencies show a general similarity to those reported for the other Italian regions.

1315 school-boys of the Cosenza province (Calabria - southern Italy) were subtyped for the PGM1 locus. Three subsamples were examined, two from the Tyrrhenian and the Ionian coasts, respectively, and one from the internal part of this province. The PGM1*1S, PGM1*2S and PGM1*2F gene frequency estimates obtained for the population of the Ionian coast were significantly different from those of the tyrrhenian coast. Since the three subsamples were of similar size, estimates weighted also with the respective population sizes were calculated.

Acid phosphatase (ACP1), adenosine deaminase (ADA), esterase D (ESD), glyoxalase 1 (GLO1), phosphogluconate dehydrogenase (PGD) and phosphoglucomutase 1 and 2 (PGM1 and PGM2) polymorphisms have been studied in the Reggio Calabria province (Southern Italy). The ACP1*A allele and ADA, GLO1, PGD and PGM1 systems have frequencies similar to those reported for Sicily and Southern Italy.

About 280 unrelated individuals living in the province of Bologna (Northern Italy) have been studied for the following red cell enzymatic markers: phosphoglucomutase (PGM), adenylate kinase (AK), adenosine deaminase (ADA) and phosphohexose isomerase (PHI). 116 subjects from the same sample have also been analysed for red cell acid phosphatase (ACP). The observed gene frequencies are PGM21 = 0.280; AK2 = 0.030; ADA2 = 0.091; ACPa = 0.297; ACPb = 0.647; ACPc = 0.056. In the PHI system two individuals with the variant PHI 3-1 phenotype have been found.

Phosphoglucomutase (PGM1) phenotypes were determined in a population sample of Tuscany, Italy, by isoelectric focusing. The frequencies observed for the four alleles are: PGM1+1 = 0.6012, PGM1-1 = 0.1059, PGM2+1 = 0.2495, PGM2-1 = 0.0434. Two variants were detected and it was possible to study the parentage of both of them. The pedigree of the propositus of the first variant shows that the variant occurs in combination with the common alleles PGM1 1+ and PGM1 2+ and that it has an autosomal dominant inheritance. The second variant has been shown to be a product of the PGM2 locus, although its PAGIF pattern is included between 2- and 1+ isoenzymes.

A rare phenotype at the phosphoglucomutase locus 1 with an electrophoretic mobility similar to that of PGM1 8-1 was found in an Italian family. The study of this variant was performed by isoelectric focusing on polyacrylamide gel. Also the isoelectric point of the PGM81 gene product was determined.

About 3,500 subjects from Italy and Czechoslovakia have been analyzed by acid starch gel electrophoresis for the subtyping of PGM1 polymorphism. The Italian sample included three different subgroups, from Northern, Central and Southern Italy. The allele frequencies found in the three groups do not differ significantly from each other; the observed values in the pooled sample are: PGM1S1 = 0.594, PGM1F1 = 0.118, PGM2S1 = 0.231, PGM2F1 = 0.057. In the Czechoslovakian group, which differs significantly from the Italian population, the following allele frequencies were found: PGM1S1 = 0.639, PGM1F1 = 0.118, PGM2S1 = 0.180, PGM2F1 = 0.063. The analysis of 217 families did not show any exception to Mendelian inheritance of the patterns.

A sample of unrelated individuals, born and living in South Sardinia, was studied with respect to the enzymes 6PGD and PGM1. The gene frequencies were: PGDA 0.989 and PGM1 0.790. The results were compared with those of other Italian populations.

The occurrence of PGM1 phenotypes in 589 samples from the population of Padua was investigated by ultrathin-layer isoelectric focusing. All ten phenotypes were observed. Frequencies of the PGM1 alleles (1+ = 0.6180; 1- = 0.1163; 2+ = 0.2122; 2- = 0.0535) have been compared to those found in other populations.

Acid phosphatase (ACP1), esterase D (ESD) and phosphoglucomutase 1 (PGM1) polymorphisms have been studied in Sardinia and the following gene frequencies have been found: ACP1*A = 0.235, ACP1*B = 0.684 and ACP1*C = 0.081; ESD*2 = 0.118 and PGM1*2 = 0.233. These findings confirm the genetic uniqueness of Sardinians compared to the other Italian and European populations.

Adenylate kinase (AK), phosphoglucomutase (PGM1) and 6-phosphogluconate dehydrogenase (6PGD) polymorphisms were investigated in a sample of individuals from Central Sardinia. The gene frequencies were: AK1 = 0.973, PGM1(1) = 0.842 and PGDA = 0.969. The frequencies were compared with those of other Italian populations.

The electrophoretic and thermostability polymorphisms of the PGM1 locus were examined in about 700 Czechoslovakians (Prague) and 3000 Italians. The Italian sample consisted of individuals from Pavia (Northern Italy), Viareggio and Rome (Central Italy) and Naples (Southern Italy). The eight PGM1 alleles, PGM1Str1, PGM1Sts1, PGM1Ftr1, PGM1Fts1, PGM2Str1, PGM2Sts1, PGM2Ftr1, PGM2Fts1, have been considered as combinations of mutations at three different sites, 1/2, S/F and tr/ts, within the PGM1 gene and their frequencies discussed in terms of linkage disequilibrium between these sites. All pairwise differences between the samples were significant except for Pavia-Viareggio and Viareggio-Rome. The frequencies of the PGMts1 alleles have been found to range from 0.0981 (Prague) to 0.0546 (Naples) and can be ordered according to a North-South cline.