Genetics of Risk
Helps the physician to anticipate the disease and thus prevent it or minimize its effects
Genetics and Prevention
Most diseases affecting adults (diabetes, hypertension, hyperlipidemias, osteoporosis, cardiopathies, cancer, dementia, ictus, etc.) are included in the concept of polygenic diseases, characterized by multiple genetic defects in different regions of the human genome, which make us more susceptible to the disease when faced with certain environmental conditions. These pathologies constitute one of the major causes of disease and death worldwide, causing disabilities and considerable sociomedical expenditure.
Due to the interaction between genes and environment, complex diseases may be forestalled by acting on the environmental factors with an appropriate prevention plan.
Knowledge of the genes involved in the development of these diseases enables us to make certain predictions regarding the risks, susceptibilities or resistance to developing them.
What is Genetic Risk?
The term susceptibility, genetic predisposition, or genetic risk of suffering a particular disease is defined as the presence of certain variations in the DNA sequence and/or the combination of a series of these (haplotypes) in an individual; while these are not necessarily abnormal, when associated they may increase the risk of developing a particular disease. In other words, a person has inherited a copy of the “problem gene” from his/her parents; while this in itself is not a causal agent, it does make the person more susceptible to developing a disease. If the environmental conditions are appropriate and an interaction with the “problem gene” occurs, the disease will appear.
Familial history is an important factor when estimating an individual’s risk or susceptibility to developing a particular disease. If a father has a particular disease, this does not mean that his son will necessarily suffer it; the risk therefore cannot be calculated, but only estimated.
What factors of an individual’s familial history make him/her more susceptible to a particular pathology?
- Having two or more family members with a particular disease.
- Having a family member with a disease diagnosed before the age of 55..
- Having a family member diagnosed as having a disease which is uncommon in a particular gender (e.g. myocardial infarction in women).
- The presence of two or more diseases in a family (e.g. diabetes and cardiovascular disease).