Are genes 100% responsible for hereditary health problems or are common habits and routines responsible as well?

I think it’s a combination of both. For example, teeth, there is a hereditary component to your susceptibility to cavities…it doesn’t mean it will happen if your parents don’t have good teeth, but the likelihood is far greater than a kid whose parents have good teeth.

One way to study this would be to look at adopted kids, if you could track their birth parents compared to their adoptive parents situation…I wonder if there are any studies like that…

Good question!

It depends on the health problem in question. There are some diseases that are 100% genetic. The classic example of this is Huntington’s disease. Many health conditions seem to have a genetic basis, but we can’t isolate the gene for it and can’t be certain how much genes contribute.

Since you asked specifically about obesity, there are many, many causes and I think it is safe to assume they are all being studied extensively. Some people’s obesity is 100% genetic, some people’s obesity is 0% genetic, and most people fall somewhere in between.

I think what you are asking about fundamentally is the nature/nurture debate. Yes, genes and environment both contribute to most hereditary illnesses, and both are taken into account when scientists study them.

It’s a combination of both. I would look into seeing if there were any split-up twin studies done regarding health and nature vs nurture. Of course, I highly recommend all split up twin studies, as they are interesting and wonderful at examining many aspects of the nature versus nurture debates.

I am a Biomedical Science graduate and it is a foregone conclusion that it is a combination of both.

Your genes are responsible for predispositions to certain illnesses, as well as susceptiblities and resistances to other infections and ailments. For instance, the european gene pool have an innate resistance to influenza, but vulnerabilities to less common illnesses in that population will remain.

In many cases, some people will be unable to influence the predisposition to certain illnesses is so strong there is little that can be done with treatment or any form of control, such as downs syndrome, fragile x syndrome, etc. There are also predispositions which can either not be influenced, or are weak enough so that an envrionmental trigger would be required, such a high intake of animal fats, depending on the strength of the predisposition, such as heart disease. Some people will find it hard to avoid, however, others will have a chance of avoiding it under the provision that they follow a stricter diet or take statins way before the onset of the condition.

Many of these genetic diseases require a “repeating unit” threshold to be higher than a certain level. For instance, you would need in your DNA a sequence to repeat over 50 times in order for you to have the condition. If your parents have, say, 30 each, you could inherit more than 30 from them, resulting in you having the disease, with them not showing it.

There is then the dominance of said genes causing such diseases. If something is dominant, having just 1 copy would result in you exhibiting the symptoms of the disease, without much envrionmental factors can do to influence it. If a disease is recessive, you would require both copies in your chromasomes to exhibit the disease. However, if you carry only 1, the disease would be suppressed, or alternately, only mildly exhibited, for example, in sickle cell anaemia. Alternately, some treatment and diets can help people cope with these infections, which easily ameliorate the symptoms, further lending to the concept that both genes and envrionment can influence many diseases.

As you can tell, there are many ways genes can affect diseases as well as help/hinder us fighting off infections. In immune flaws, people can be rendered totally unable to fight off typically simple infections, such as in the story of dede the tree man. He is unable to control a simple wart causing virus, resulting in his body being consumed by these normally, mildly irritating viral infections.

I could go on all day, however, I think this is enough :)

Are genes 100% responsible for hereditary health problems? YES

Are common habits and routines responsible as well? NO

If a trait is influenced by habits or routines, that habit or routine is the cause.

i.e. you may come from several generations of alcoholics, but if you never indulge, you will not become one.