DNA methylation is one of the principal epigenetic mechanisms through which the environment can leave durable imprints on the genome without altering the underlying DNA sequence. It involves the addition of methyl groups to cytosine residues at CpG dinucleotides, which can suppress or modulate gene expression. These marks are laid down with particular dynamism during early embryogenesis and placental development, and they are sensitive to maternal nutrition, stress, and metabolic state. According to the Developmental Origins of Health and Disease framework, such intrauterine exposures can induce persistent molecular alterations that shape growth trajectories, energy metabolism, and adiposity regulation throughout life, providing a plausible biological bridge between the prenatal environment and chronic disease risk decades later.

The placenta sits at the interface between maternal and fetal circulations, mediating the flow of nutrients, hormones, and immune signals that sculpt fetal growth. Epigenome-wide association studies have previously identified placental loci whose methylation levels correlate with metabolic outcomes in offspring, positioning the placenta as both a biosensor of prenatal conditions and a potential effector of metabolic programming. But a crucial question has remained open: do methylation marks established before birth persist across tissues into postnatal life, and can they be traced across generations within a family? The Girona study was designed to address exactly this gap, using the ASPG gene as its molecular probe.

ASPG is an unexpected candidate for obesity research. The enzyme it encodes has long been deployed as a chemotherapeutic agent against acute lymphoblastic leukemia, where it depletes circulating asparagine and starves tumor cells dependent on extracellular supplies of this amino acid. Beyond oncology, asparagine biology intersects with central metabolic signaling pathways, including mechanistic target of rapamycin, AMP-activated protein kinase, and sterol regulatory element-binding protein 1, all of which govern lipid and glucose metabolism. Experimental work in mice has shown that hepatic ASPG expression is induced under metabolic stress, promoting lipid accumulation, inflammation, and insulin resistance, while human studies have linked elevated circulating asparagine levels with metabolic syndrome, obesity, and type 2 diabetes risk. Recent work has also demonstrated that hepatic ASPG negatively regulates insulin signaling in humans.

The investigation drew on the Girona Prenatal Study, a population-based prospective cohort that recruited families during routine antenatal visits. Participants were selected under strict criteria: Caucasian origin, singleton pregnancies, term delivery between 37 and 40 gestational weeks, and written informed consent from both parents. Mothers with pregestational or gestational diabetes, hypertension, preeclampsia, or other obstetric complications were excluded, as were pregnancies involving fetal growth restriction, neonatal malformations, or assisted reproductive technologies. Genome-wide methylation profiling of 24 placental samples using the Illumina Human MethylationEPIC BeadChip had previously flagged a CpG site, cg20965743, within the gene body of ASPG as associated with childhood body mass index standard deviation scores. The team then validated this signal by pyrosequencing in an independent set of 180 placentas.

The validation succeeded. Placental ASPG methylation correlated positively with weight-SDS, BMI, and BMI-SDS at six years, and with the longitudinal change in weight-SDS from birth to age six, suggesting the mark tracked not merely with size at one moment but with divergent growth trajectories. Correlations extended to systolic blood pressure and carotid intima-media thickness, an early vascular marker of cardiovascular risk. All of these associations survived adjustment for child age, sex, maternal pre-pregnancy BMI, gestational age, and birth weight, and additional adjustment for maternal smoking, gestational weight gain, and maternal glucose levels did not materially alter the estimates. In logistic regression, each unit increase in placental ASPG methylation raised the odds of overweight or obesity by six percent, and children in the top quartile of methylation faced roughly 1.47-fold higher odds than those in the bottom quartile.

The cross-tissue analyses added a compelling layer. Among 127 children with paired blood samples, ASPG methylation in peripheral blood at age six showed the strongest correlation with weight gain from birth, along with associations with waist and hip circumference, ultrasound-measured subcutaneous and visceral fat, LDL-cholesterol, and triglycerides. Blood methylation carried a somewhat stronger obesity signal than the placenta, with an adjusted odds ratio of 1.19 for overweight or obesity and an approximately 2.4-fold difference between the top and bottom methylation quartiles, though these blood analyses were cross-sectional and therefore vulnerable to reverse causation. Crucially, methylation levels in child blood correlated with levels in the placenta collected six years earlier, at a correlation coefficient of 0.40, indicating that at least some of the epigenetic information written before birth persists into childhood blood.

The family-level patterns were perhaps the most provocative. Maternal ASPG methylation measured in leukocytes during the second trimester correlated with child methylation at a coefficient of 0.48, while paternal methylation showed no correlation with any other tissue. The authors propose several non-exclusive explanations. After fertilization, paternal DNA undergoes predominantly active demethylation, whereas maternal DNA is largely passively demethylated, an asymmetry that could differentially preserve methylation patterns across generations. Alternatively, the mother-child concordance may simply reflect shared intrauterine exposures that shape maternal and fetal methylation in parallel, mimicking inheritance without meiotic transmission. Distinguishing between these possibilities would require maternal methylation measurements outside pregnancy, which the current study could not provide.

The researchers are careful about the limitations, and readers should be too. Effect sizes were modest, with correlation coefficients ranging from roughly 0.15 to 0.27, consistent with the multifactorial nature of obesity, in which any single epigenetic mark contributes only a sliver of overall risk. The parental analyses rested on just 44 families and are explicitly exploratory, potentially underpowered to detect small effects. Methylation was quantified at a single CpG site in heterogeneous cell populations, leaving open whether the associations reflect cell-type composition shifts or genuine regulatory changes. The authors also note that the predictive value of ASPG methylation was not formally assessed, so its clinical utility as a screening tool remains unproven. Individual loci should not be read as strong personal predictors but as windows into early-life biological processes.

Still, the study is the first human investigation to trace ASPG methylation across placenta, child blood, and parental blood in relation to childhood adiposity, and its prospective design gives the placental findings genuine temporal weight. The convergence of a birth-time epigenetic mark with cardiometabolic outcomes measured six years later, its persistence across tissues, and its apparent maternal concordance together sketch a coherent picture of early metabolic programming. Whether ASPG methylation ultimately earns a place in risk stratification will depend on replication in independent and more diverse cohorts, functional assays in metabolically relevant tissues, and multigenerational sampling that can separate true inheritance from shared environment. For now, the work adds an intriguing molecular character to the growing cast of placental genes that may whisper, from the first days of life, something about the metabolic road ahead.

Subject of Research: Association between placental asparaginase gene DNA methylation and childhood obesity in a prospective birth cohort

Article Title: Asparaginase methylation and childhood obesity: cross-tissue patterns and parent–child concordance in a prospective cohort

Article References: Niubó-Pallàs, M., Gómez-Vilarrubla, A., Mollà-Martínez, J., Mas-Pares, B., Bonmatí-Santané, A., Martínez-Calcerrada, J.-M., de Zegher, F., Ibáñez, L., López-Bermejo, A., & Bassols, J. (2026). Asparaginase methylation and childhood obesity: cross-tissue patterns and parent–child concordance in a prospective cohort. World Journal of Pediatrics. https://doi.org/10.1007/s12519-026-01071-0

Image Credits: AI Generated

DOI: 10.1007/s12519-026-01071-0

Keywords: DNA methylation, epigenetics, childhood obesity, placenta, asparaginase, ASPG gene, developmental origins of health and disease, prospective cohort, adiposity, maternal-fetal, pediatrics, cardiometabolic risk