We already know of some intimate relationships between the blood type gene and other genes that impact on our health and well-being. For example, in 1984, researchers reporting in the journal Genetic Epidemiology presented evidence of a family pedigree in which a major gene for breast cancer susceptibility is located near band q34 on chromosome 9. There is a clear genetic connection between blood type and breast cancer. Many nutrition experts are baffled when they first hear about the link between blood type and digestion. That's because they are only considering the physical significance of blood type as a surface antigen.
Many genes influence the actions of other, seemingly unrelated genes.
Here's another intriguing link that suggests a relationship between blood type and the brain. It's literally sitting on top of the gene for blood type. As we will see later, this has vast implications for the association between blood type and stress, mental health, and even personality characteristics. The reality is far more intricate and complex. Now, let's take it to another level.