Genes involved in determining a baby's birthweight may also predispose them to diseases in later life, such as heart disease and type 2 diabetes, a global study has found.
The study, which analysed more than 153,000 individuals, also found that genes play a much more significant role in determining birthweight than had been previously thought.
Researchers from 117 institutions in 17 different countries took part in the Early Growth Genetics (EGG) consortium. They found at least 60 regions in the genome that affect birthweight, accounting for around 15 percent of the variation in birthweight between babies. Earlier, it had been thought that genes account for just two percent of the variation in birthweight.
Many of these genetic variants have been linked to diseases of later life – high blood pressure, type 2 diabetes and coronary artery disease were linked to a low birthweight, whereas greater waist circumference and adult height were associated with a higher birthweight.
'We see a pretty substantial overlap, which tells us that some of that link that people are observing in populations across the world must be mediated through shared genetic variants that are having an impact both on early life, and then 60–70 years later the same genetic differences impact on whether you are likely to get diabetes or not,' Dr McCarthy told The Guardian.
'The next step must include analysis of these gene pathways in tissues from pregnancy cohorts, and biosamples from adults with and without metabolic diseases, to work out exactly how these genes are involved in producing these effects,' added Dr McCarthy.
The researchers say that the study could help scientists understand how diseases such as type 2 diabetes arise and find ways to prevent and treat such conditions.