Parent-of-origin effects in the life-course evolution of cardio-metabolic traits

ObjectiveHuman traits are heritable, and some of these including metabolic and lipid phenotypes show preferential parental transmissions, or parent-of-origin effects. These have been mostly studied in populations comprising adults. We aimed to investigate heritability and parent-of-origin effects on cardiometabolic and anthropometric traits in a birth-cohort with serial measurements to assess if these effects manifested at an early age. Research design and methodsWe investigated heritability and parent-of-origin effects on cardiometabolic and anthropometric traits in the Pune Maternal Nutrition Study (PMNS) wherein offspring and parents were studied from birth and followed-up for 18 years. Heritability was estimated by calculating association between mid-parental phenotypes and offspring. Maternal and paternal effects on offspring phenotype were modelled by regression after adjusting for age, sex and BMI. Parent-of-origin effects were calculated by the difference between maternal and paternal effects. ResultsAnthropomorphic traits and cardiometabolic traits were robustly heritable. Parent-of-origin effects were observed for glycemic traits at both 6- and 12-years, with a paternal effect at 6-years which transitioned to a maternal effect at 12-years. For insulin and HOMA-S, a negative maternal effect transitioned to a positive one at 12-years. For HOMA-B, a paternal effect at 6-years transitioned to a maternal one at 12-years. Lipid traits consistently showed stronger maternal influence while anthropometric traits did not show any parental biases. ConclusionsOur study highlights that parental programming of cardiometabolic traits is evident from early childhood and can transition during puberty. Further studies are needed to determine the mechanisms of underlying such effects.