One of the features that can be of most use when GenoTyping someone is actually one of the hardest to come by: Getting the ABO blood groups of your parents.

Its importance should come as no surprise, since epigenetic changes are largely influenced by the patterns of gene activation and silencing that occur as part of

• The heritable epigenetic component (you start off with the patterns of gene expression that your parents give you)
• The prenatal environment (there are two major bursts of methylation activity in the fetus: at about 8-12 weeks, then again in the last trimester)
• The immediate postnatal environment (these are mostly related to gene expression due to hormones such as growth factors)

In fact one of the studies that got me interested in the largely unrecognized effects of blood groups as a modulator of the epigenetic environment was a study that looked at childhood ear infections and blood groups. However, unlike most epidemiologic correlation type studies, this one looked at the blood group of the child’s mother.

Maternal blood group A gave a relative risk (RR) for intervention of 2.82. The noted occurrence of an attack of acute otitis media (AOM) before the first birthday gave a RR of 6.13. When these two factors were used together, the RR climbed steeply to 26.77.

Now to understand just how strong this association is we should look at exactly what a RR (relative risk) is. Basically it is just the odds (over 1) that something will occur over it being random. An RR of 2 (about the RR of elevated cholesterol causing a heart attack) means that people with elevated cholesterol are twice as likely to get a heart attack as people whose cholesterol levels are more desirable. Thus the study is saying that if you are a kid with an ear infection in the first year of life, and you mother is blood group A, you are 26 times more likely to have a recurrence.

Here is a chart I made which compares relative risks for several common problems and factors associated with that risk. Obviously, this is a very strong association.

Are the effects of having a blood group A mother and getting ear infections the result of some sort of fetal programming? We know that some studies have linked the ABO antigens to cellular differentiation (the process where developing cells move from general embryonic 'germ' types to cells with more specific functions, like a pancreatic or epidermis cell.)

ABH antigen expression was considered as suggestive evidence for the assumption that blood group antigens could serve as early immunomorphologic markers of endothelial differentiation of mesenchymal cells, thus specifying the location of future blood vessels. Extending the conceptual framework of blood group antigens' significance we consider them as being possibly involved in the process of fetal morphogenesis.

In epigenetic terms, we may wind up being more interested in your parent's blood types are that perhaps we need be with yours.

Every once in a while, amid the junk mail, bills and catalogs, I receive a letter which surpasses all prior. In a wonderfully sycophantic endeavor this gentleman writes to ask me for a complete set of my works so he can continue on his mission to educate the Indian public about healthy living. Apparently the gentleman does it free of charge.

Sir, your books are on their way.