Epigenetic regulation of Newborns' imprinted genes related to gestational growth: patterning by parental race/ethnicity and maternal socioeconomic status.
BACKGROUND
Children born to parents with lower income and education are at risk for obesity and later-life risk of common chronic diseases, and epigenetics has been hypothesised to link these associations. However, epigenetic targets are unknown. We focus on a cluster of well-characterised genomically imprinted genes because their monoallelic expression is regulated by DNA methylation at differentially methylated regions (DMRs), are critical in fetal growth, and DNA methylation patterns at birth have been associated with increased risk of birth weight extremes and overweight status or obesity in early childhood.


METHODS
We measured DNA methylation at DMRs regulating genomically imprinted domains (IGF2/H19, DLK1/MEG3, NNAT and PLAGL1) using umbilical cord blood leucocytes from 619 infants recruited in Durham, North Carolina in 2010-2011. We examined differences in DNA methylation levels by race/ethnicity of both parents, and the role that maternal socioeconomic status (SES) may play in the association between race/ethnic epigenetic differences.


RESULTS
Unadjusted race/ethnic differences only were evident for DMRs regulating MEG3 and IGF2; race/ethnic differences persisted in IGF2/H19 and NNAT after accounting for income and education.


CONCLUSIONS
Results suggest that parental factors may not only influence DNA methylation, but also do so in ways that vary by DMR. Findings support the hypothesis that epigenetics may link the observed lower SES during the prenatal period and poor outcomes such as low birth weight; lower birth weight has previously been associated with adult-onset chronic diseases and conditions that include cardiovascular diseases, diabetes, obesity and some cancers.
['King|Katherine|K|http://orcid.org/0000-0001-8615-1894', 'Murphy|Susan|S|', 'Hoyo|Cathrine|C|']
D001724:Birth Weight D015331:Cohort Studies D019175:DNA Methylation D044127:Epigenesis, Genetic D005006:Ethnicity D005312:Fetal Blood D047109:Fetal Development D018392:Genomic Imprinting D006801:Humans D007231:Infant, Newborn D009657:North Carolina D009765:Obesity D010290:Parents D012044:Regression Analysis D012923:Social Class D013995:Time
GENETICS PERINATAL EPIDEMIOLOGY Social and life-course epidemiology