Every physical feature you have, you have your parents, grandparents, aunts, uncles and a bunch of ancestors to thank for. Likewise, certain health conditions too can be inherited through those unique genes you got from mom and dad. Fortunately (and sometimes not so), environment strongly influences which of your specific (read unique) genetic traits actually reach their potential. So any trait, good or bad may not ever become visible in you because of your lifestyle choices, environment and other outside factors.
You may have the gene of a basketball player but never grow to your full height if you were under-nourished as a child. You may have a long ancestry of heart disease but if you ate healthy, were physically active, and chose not to smoke or drink through your lifetime, you may never run into heart problems.