Were you a tiny tot or a tubby toddler? If so, your mom’s folic acid intake could be to blame. As those of us in the U.S. prepare to indulge in a Thanksgiving Day gorge-fest, here’s more proof that we are what our mothers ate. A recent study by William Farrell and colleagues in the U.K. has linked homocysteine levels in fetal cord blood with gene-specific methylation patterns and birth weight in newborns.
Doctors have long recommended folic acid supplementation during pregnancy. Insufficient levels of this methyl donor increase the risk of neural tube defects and low birth weight. Homocysteine is an inverse indicator of blood folate and methyl group levels: low folate = high homocysteine = fewer methyl groups to methylate DNA and other substrates.
Farrell and colleagues profiled DNA methylation patterns in 12 fetal cord blood samples using the Illumina Infinium Methylation 27K bead array, which examines the methylation states of 27,578 CpG loci at single-nucleotide resolution. They identified two clusters of babies with similar DNA methylation patterns: one cluster correlated with low birth weight and high homocysteine levels, while the other cluster tended to have higher birth weights and lower homocysteine. This data lead the team to think that homocysteine levels in cord blood are a potentially powerful predictor of birth weight.
These findings strengthen the link among methyl donors, gene-specific methylation, and pregnancy outcome. By examining the specific methylation patterns in more detail, the researchers may be able to identify regions important in fetal development.
So go ahead, have a second slice of pumpkin pie (a good source of folic acid), and check out this paper at Epigenetics, January 2011.