Experience with any identical twins quickly reveals that they are not clones one of another. Personality, demeanor, preferences, and other factors are very similar but not 100% copies. In terms of health, twins have a higher rate of sharing certain diseases, but rarely 100% there either. In the functional medicine world, we always say that while genetics loads the gun, environment pulls the trigger. From early on, twins are exposed to different trigger pulling.
Scientists are uncovering how some of these differences turn up long periods of time after the trigger is pulled. When an adulthood disease links back to a childhood trigger, a mechanism for such a delay must be present. Methylation of genes serves as one of these mechanisms. Methylation turns genes down or off, meaning the gene does not get turned into a protein as often.
In this interesting study from Thyroid, researchers compared the effects of differing methylation patterns in specific genes on whether one identical twin develops an autoimmune disease and the other one does not.
By looking at 23 pairs of identical twins in which one had anti thyroglobulin antibodies and the other didn’t, researchers uncovered four genes that when methylated differently played a part in this difference. Interestingly, these genes which produced the difference were not the same that put one at risk for autoimmune disease.
We are just scratching the surface in understanding how methylation affects our health.
Osaka University. “Immune diseases inflict identical twins differently: Scientists explain why only one identical twin is at risk for autoimmune diseases.” ScienceDaily. ScienceDaily, 12 December 2017. www.sciencedaily.com/releases/2017/12/171212102044.htm