The first concrete evidence of a genetic link between low birth weight and the potential for developing type 2 diabetes has been published in the April 6 issue of the journal Nature Genetics. Scientists previously believed that lower birth weight babies were more at risk, but the cause remained unclear.
Environmental factors like maternal diet and breastfeeding versus bottle-feeding have been in the news as factors that can alter the development of type 2 diabetes later in life. The current study confirms that genetics also play an important role.
Mark McCarthy of the Oxford NIHR Biomedical Research Centre and a team of scientists from around the world analyzed data from 19 previous pregnancy studies including over 38,000 European subjects and found that two genetic variants were linked to birth weight, including a variant in a gene called ADCY5 that has previously been linked to blood glucose regulation and type 2 susceptibility.
With two copies of the variant, the risk of developing type 2 diabetes is 25 percent greater than if neither copy of the gene has the variant. Nine percent of Europeans inherit two copies of a genetic variant and are, on average, 113g (4 ounces) lighter at birth than the 24 percent who inherit one or no copy.
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Nature Genetics, April 6, 2010