The genetics of signal transduction and the feto-maternal relationship. A study of cytosolic low molecular weight phosphotyrosine phosphatase

Maternal genome-wide DNA methylation patterns and congenital heart defects

The majority of congenital heart defects (CHDs) are thought to result from the interaction between multiple genetic, epigenetic, environmental, and lifestyle factors. Epigenetic mechanisms are attractive targets in the study of complex diseases because they may be altered by environmental factors and dietary interventions. We conducted a population based, case-control study of genome-wide maternal DNA methylation to determine if alterations in gene-specific methylation were associated with CHDs. Using the Illumina Infinium Human Methylation27 BeadChip, we assessed maternal gene-specific methylation in over 27,000 CpG sites from DNA isolated from peripheral blood lymphocytes. Our study sample included 180 mothers with non-syndromic CHD-affected pregnancies (cases) and 187 mothers with unaffected pregnancies (controls). Using a multi-factorial statistical model, we observed differential methylation between cases and controls at multiple CpG sites, although no CpG site reached the most stringent level of genome-wide statistical significance. The majority of differentially methylated CpG sites were hypermethylated in cases and located within CpG islands. Gene Set Enrichment Analysis (GSEA) revealed that the genes of interest were enriched in multiple biological processes involved in fetal development. Associations with canonical pathways previously shown to be involved in fetal organogenesis were also observed. We present preliminary evidence that alterations in maternal DNA methylation may be associated with CHDs. Our results suggest that further studies involving maternal epigenetic patterns and CHDs are warranted. Multiple candidate processes and pathways for future study have been identified.

ABH secretor genetic polymorphism: evidence of intrauterine selection

OBJECTIVE

Fucosyltransferase locus 2 (FUT2) controls the presence or absence of blood group substances (A, B, H) in the saliva and other body secretions. Secretor/non-secretor phenotypes are associated with some metabolic and infectious diseases. ABO and FUT2 contribute to build up oligosaccharide structures of the cell surface that are important for blastocyst adhesion and resistance to microbial invasion. We investigated a possible selection on ABH secretor phenotypes during intrauterine life.

STUDY DESIGN

Three hundred and fifty-six consecutive healthy puerperae and their newborn infants from the caucasian population of Rome were studied. Informed consent for study participation was obtained from the mothers to participate and the study was approved by the Institutional Review Board. ABH secretor Se phenotype was determined on saliva by standard laboratory procedure.

RESULTS

Symmetry analysis of mother infant Se phenotype revealed a deficit of mother Se+/newborn Se- with respect to expected values. The asymmetry is present only in infants carrying the A blood group antigen. The asymmetry was dependent on several maternal and neonatal parameters including maternal age, smoke, parity and gestational duration.

CONCLUSIONS

The data suggest intrauterine selection against Se- of the embryo carried by a Se+ mother. Such selection is dependent on factors influencing the maternal environment. The study could have practical importance in assessing the risk of infertility and success of artificial insemination.

Feto-maternal ACP1 activity ratio and intrauterine survival

OBJECTIVE

Genetic differences in the activity of phosphotyrosine phosphatases between mother and embryo could result in a differential activation of signals induced by growth factors in the two sides of placenta. Previous observations suggest that this may have important effects on intrauterine development and survival. The aim of the present study is to confirm previous observations and show new data.

STUDY DESIGN

We have studied 573 mother/newborn pairs, 169 wife/husband couples with repeated spontaneous abortion and 34 fertile wife/husband couples

RESULTS

In mother/newborn pairs, the analysis of joint mother/infant ACP1 distribution has shown a deficit of pairs with the mother having low ACP1 S isoform concentration and the infant having high S isoform concentration, and an excess of pairs with the mother having high S isoform concentration and the infant having low S isoform concentration. In RSA couples there is an excess of couples in which the wife has low S isoform concentration and the husband has high S isoform concentration and a deficit of couples in which the wife has high S isoform concentration and the husband has low S isoform concentration. In fertile couples the pattern is reversed.

CONCLUSION

The data suggest that when the mother to fetus S isoform concentration ratio is in favour of the mother, the probability of survival of the fetus is greater than in the opposite situation.