Uninherited parental genes leave lasting imprint on children’s lives
A study published in Cell Genomics by researchers at the Institute of Science and Technology Austria (ISTA) and the Norwegian Institute of Public Health found that parental genes influence a child’s height, body weight, and school performance through the environment they create. This “genetic nurture” can be nearly as significant as the DNA a child inherits directly, according to the research team.
Professor Matthew Robinson of ISTA led the study alongside postdoctoral researcher Ilse Krätschmer and Alexandra Havdahl, Director of the PsychGen Center for Genetic Epidemiology and Mental Health at the Norwegian Institute of Public Health. The team developed a new method to separate direct genetic contributions from indirect parental influences and parent-of-origin effects.
How do parental genes influence children beyond DNA?
Parents do more than pass on genetic sequences. Their own genetic makeup shapes parenting behavior and the household environment, a process the researchers call “genetic nurture.” Robinson stated that indirect genetic effects and parent-of-origin effects are distinct phenomena that explain how genes influence traits beyond a person’s direct DNA.
The “parent-of-origin effect” occurs when certain genes are naturally switched off in either sperm or eggs. This means some genetic variants only have an effect if they are inherited from the parent where the gene remains “on.” This mechanism may explain why identical genetic sequences result in different metabolic or physical characteristics, according to the study.
What did the study of 30,000 families reveal?
The researchers tracked three specific traits in children: height, body mass index (BMI), and national school test scores taken around age 10. While a child’s own DNA remained the largest source of variation for all three, the combined impact of indirect parental and parent-of-origin effects was “similarly substantial.”
Krätschmer noted that similar DNA regions, or “loci,” often underlie both direct and indirect genetic effects. This suggests the same loci can shape a child’s traits through the genes they carry and the environment their parents provide.
The data showed that environmental factors played the largest role in determining education scores and BMI. Because of this, the researchers suggest that policies designed to improve education or health outcomes may need to account for the influence of the family environment.
How could these findings change personalized medicine?
The new framework may be extended to study other conditions, including metabolic diseases and mental health disorders. Krätschmer stated the method allows researchers to pinpoint if a genetic effect is associated only with a parent’s DNA and not the child’s own.
The researchers suggest that only regions of direct genetic effect are likely to be effective drug targets in personalized medicine, as these tend to have a stronger impact within the individual. Additionally, Robinson concluded that the results suggest genetic imprinting may be widespread in humans, though the underlying mechanisms are not yet fully understood.
Frequently Asked Questions
What is genetic nurture?
Genetic nurture is the phenomenon where a parent’s genetic makeup shapes the household environment and parenting behavior, which then influences the development of the child.
What is the parent-of-origin effect?
It is a process where some genes are switched off in either the egg or sperm, meaning the gene’s effect depends on which parent passed it down.
Which traits were most influenced by the environment?
According to the study, environmental factors played the largest role in children’s BMI and school test scores.
Which of your own traits do you think were shaped more by your environment than your DNA?