Weight of genetics in the development of diseases
If genetic disease is caused by the mutation of a single gene, it is a “monogenic” disease. There may be additional mutations in other genes, but just one can cause a disease.
Other diseases are known as “complex” (they can also be called polygenic or multifactorial) and will depend on the interaction between the individual’s genetics, their lifestyle and/or external risk factors. In such cases, reference can be made to genetic predisposition or susceptibility: certain genetic traits can increase the risk of developing a disease. On another note, certain hygienic habits can modulate this risk, increasing it, or to the contrary, providing a certain protection. External risk factors can play a role in increasing risk.
A typical example is cardiovascular disease. CV disease can be attributed to the sum of individual genetic predisposition and bad lifestyle habits that lead to the development of certain risk factors such as high cholesterol, smoking or hypertension. Someone with predisposition to suffering cardiovascular disease can control/minimize that risk by adopting a cardio-healthy lifestyle (healthy diet, exercise, etc.).
Another example is thrombosis: a person can have a genetic thrombophilic profile, giving them a higher likelihood of developing thrombosis. Personal risk factors such as older age or obesity will increase an individual’s thrombosis risk. External factors such as prolonged immobilization or certain medications can also contribute to increasing that risk. Knowing one’s genetic predisposition facilitates the implementation of prevention measures.