Genes link birth weight to adult-onset diseases

Low birth weight is linked with a number of adult diseases, including stroke, hypertension and type II diabetes, but the mechanisms underlying these connections are unclear.

A large international team led by Momoko Horikoshi of the University of Oxford in the UK, involving several research teams in Saudi Arabia, including King Faisal Specialist Hospital and Research Centre, the King Khaled Eye Specialist Hospital, and Alfaisal University in Riyadh, performed a genome-wide association study (GWAS) in nearly 27,000 people of European descent.

The GWAS data was combined with a meta-analysis of 43 previously published GWAS studies, which together amount to 69,300 Europeans. They identified four genetic variants associated with fetal growth and birth weight as well as adult height and metabolism. The analysis also confirmed three genetic variations that were reported in previous studies as being associated with birth weight.

Two of the genetic variants are known to be associated with an increased risk of type II diabetes; two others with adult height; and a fifth with adult blood pressure. The findings show that fetal growth and birth weight are genetically linked to postnatal growth and metabolism in adulthood.

The findings have no immediate clinical applications, but they could help researchers begin to understand how birth weight is related to disease later on in life.

"One of the things we want to do now is to explore the extent to which these genetic effects are the same in other ethnic groups," says Mark McCarthy of the University of Oxford, one of the senior authors of the study. "Different ethnic groups have markedly different ranges for birth weights and it will be interesting to see if the genetics can help to explain that in any way.

"The second thing is to work on these regions more carefully and tease out what exactly is going on to alter birth weight — which genes in these regions is the key player."

Sign-up to receive our e-alert update every two weeks to keep up with everything new on the portal.