MBS BLOG # 8
Genetics and Mind Body Syndrome
Everyone knows that genes “controls” our lives. But how powerful an influence do our genes play in our lives? Of course, these issues have been debated for many years since the discovery of genes and the classic experiments of Gregor Mendel in 1865 on pea plants genetics. We wonder not only at the similarities of facial features of children and their parents, but also at their personality quirks that seem to be passed down through genes. There have been many books that purported to show that genes control everything. So, when we are told that a certain disease is genetic. We often assume that we are destined to be affected and that treatment may have little effect.
First, you must realize that there are certain genes that do have powerful effects that will produce diseases if those genes are present. For example, cystic fibrosis and sickle cell anemia are diseases produced by inherited genes. If you have those genes, you will get the disease. However, it is also clear that different people with the same genes can have differing levels of that disease, even in CF and sickle cell.
Other diseases have some contributions from genes, but these contributions are either minor or variable. For example, breast cancer has been found to have genetic components, but most people with breast cancer do not have the breast cancer gene. There are genetic contributions to asthma and migraine headaches, but these are relatively small contributions in comparison to the effects of genes on height, ADHD and schizophrenia, which have heritability factors of 0.8-0.9. The heritability factors of asthma and migraine headaches are in the range of 0.4-0.5, i.e. much smaller effects.
Fibromyalgia has been linked to certain genes as well, but this relationship is probably even smaller than in migraine headaches. For example, a twin study conducted in Finland did not show any genetic link, while a similar study in Sweden showed a 29% concordance rate for identical twins versus a 16% concordance rate for fraternal twins. Compare this to the 79% concordance rate for identical twins for ADHD versus a 32% concordance rate for fraternal twins for ADHD. To my knowledge, there is no evidence that back pain or neck pain has any genetic component.
So, what is the relationship between genes and disorders like migraine headaches or fibromyalgia? The best way to understand this issue is by understanding epigenetics. This is the field that looks at the role that environment plays on how our genes are affected. In other words, genes can be “turned on” or “turned off” and this is done by a huge number of regulatory proteins that are affected by what happens in our lives, i.e. what we are exposed to in our environment, everything from dust to chemicals to stress and emotions.
There is a water flea, the spiny helmet Daphnia, which can be born with or without its protective helmet. And it can grow a helmet if needed. If this flea is born without the helmet and there is a predator in the area (or even if the scent of a predator is dropped into the water), the flea will grow its helmet. In other words, the environment can send signals that create proteins that affect how the genes for growing the helmet are turned on. Recently, it has been shown that if a mother Daphnia flea is living in an area without predators, the offspring will be born without their helmets, however if the mother is exposed to the predators (or their scent), the baby fleas will be born with helmets. This is a clear example of how the environment can alter the way that genes are expressed, i.e. how the genes actually affect an organism.
What does this suggest for Mind Body Syndrome? The most important thing to realize is that genes are NOT destiny in relation to migraine, fibromyalgia, and other syndromes that make up this disorder. While scientists can identify certain genes that are found in association with these syndromes, they will not necessarily be expressed, i.e. they can be “turned on” by what happens in our lives, e.g. stress, emotions, life circumstances, but they can also be “turned off” by changes in our lives, e.g. control, understanding, acceptance, happiness, love.
Certain MBS disorders are commonly seen to “run in families” such as neck pain, headaches, stomach pains. However, we must realize that MBS is contagious (see Blog #6) and that it is very easy for certain MBS symptoms to be produced by the mind when stressful events occur in our lives. Which MBS symptoms are “chosen” by the mind depends on a lot of things, but one of those things is what might be reasonably expected. And it makes sense that our minds might expect to have a symptom that “runs in the family”, i.e. that others have.
In conclusion, be careful of how scientific information is presented with regard to genetics. Mild associations do not mean that these genes will necessarily produce a syndrome. Do not be swayed by these studies into thinking that MBS is primarily genetic. It is not.
To your health,
Howard Schubiner, MD