Genetics Problem

Before i start, i am a male, 17 years old.

My mother’s side of the family lives to be in their 80s or early 90s and generally have good health besides their circulatory system, heart attacks, strokes, etc. All of them have high cholesterol.

My father’s side of the family is almost the complete opposite, they barely get off the couch yet have normal cholesterol, no history of cardiovascular problems, no history of cancer or any other disease. The only thing that really happens when they age are stuff that happens to almost everyone, failing eyesite, forgetfulness, etc. They normally live to the ripe old ago of the upper 90’s and even pass the century mark once in a while.

My question is, giving that my two sides of my family are drastically different, what is likely to happen to me?

Have scientists been able to trace the chromosome responsible for high cholesteral and other heart problems? Given that both males and females in my mom’s family suffer from this, i would have to believe it’s a dominant gene, on the X chromosome. Or is there more too it than that?

You can’t conclude any such thing. If it occurs to males and females equally, then it’s probably not on either sex chromosone. Recessive genes on the X chromosone tend to affect males much more than females, and dominant genes on the X tend to affect females more often. Almost nothing at all is on the Y, other than the standard-issue genes for maleness.

Nor can you say that the condition is probably on a dominant gene. If everyone on your mother’s side of the family has high cholesterol, all that tells you is that the gene or genes responsible are very common on that side of your family.

To the best of my knowledge, there are a great number of genes which influence things like cholesterol levels and cardiac health, and we haven’t even found most of them. So the most likely outcome is that you’ll end up somewhere between your father’s side and your mother’s side in a variety of ways, and exactly where in between you end up is largely a roll of the dice.

More to it than that.
We know where some of the defects for some familial hyperlipidaemias (which is not the same thing as “normal” high cholesterol) are, but that’s about it. The best we can say about bog standard high cholesterol is that it is “polygenic”.

One gene is on chromosome 11q23-q24. My google-fu is weak and I can’t find a list of the others in my (fairly ancient) medical genetics textbook, but I’m sure you could find more if you looked.

Anyhow
keep your BMI under 25 and your systolic BP under 130
exercise regularly
eat lots of fruit and veg
drink moderate amounts of red wine (when you can, legally)
take a statin and aspirin when you hit 45
and you’ll be about as protected as you can be from a heart disease point of view.

Oh yes, don’t smoke either.

I’m a doctor but the above should not in any way be construed as medical advice.