Researchers at the University College London used a new approach called Genome-wide Complex Trait Analyses (GCTA) to measure heritability of genes and the impact of body mass in children.
‘The missing heritability’
“GCTA has made major inroads into explaining the ‘missing heritability’ of BMI in adults,” said the researchers.
Previous research had come up with contrasting conclusions, known as ‘the missing heritability’.
Earlier Genome-wide Association studies had associated 32 single-nucleotide polymorphisms (SNPs) with body mass index in adults, but later studies said these SNPs could only explain 2% of BMI variations in either adults or children.
Genes explain 30% of weight variations
The present study published in the International Journal of Obesity used the new GCTA method and found genetics could explain 30% of the difference between the body mass index of one child compared to another.
“These results have clinical and public health implications,” said the researchers.
“Although the method used in the GCTA analysis cannot be used to predict obesity risk for any one individual because the genetic variants involved are not identified, the results underline the importance of additive genetic effects in the development of adiposity in childhood.”
“This supports the current convention of using parental weight status as a proxy for childhood obesity risk”
They added that any health initiatives should target children of obese parents because they were most at risk.
The researchers obtained data from twins born in England and Wales between 1994 and 1996.
Source:
International Journal of Obesity (2013), 1–4
doi: 10.1038/ijo.2013.30
‘Finding the missing heritability in pediatric obesity: the contribution of genome-wide complex trait analysis’
Authors: CH Llewellyn, M Trzaskowski, R Plomin and J Wardle