The human body consists of about 50 trillion individual cells. Each of these cells has a nucleus which contains 46 chromosomes. A chromosome consists of a very closely wound thread, the DNA “double helix”. DNA, the genetic code, is the blueprint of the human body. This genetic code consists of approximately 3.1 billion molecules, which are each represented by a letter. About 1% of this code makes up the genes. Each gene is an instruction for the body, usually with a single function. For example, some genes tell the body how to generate the iris. Differences in these genes produce different eye colors. Every function of the body is controlled by one or more genes, including the way we process food and medicine.Our genes are not completely error-free. The genes of each person are changed slightly by environmental effects.
Most of these changes have no effect. A small number have a harmful effect. An even tinier number can produce a beneficial effect. Parents pass these changes, including defects, to their children. Thus most of our genetic defects are inherited from our parents. In addition, our genes developed to help us live in the primitive world, and some of the traits in our genes can interact with our modern environment to create negative effects on our world.
For example, the genetic predisposition to build up fat quickly and lose it slowly is beneficial for people who go through times when food is scarce: they will have a better chance of surviving because their bodies use fat efficiently. However, in the modern world, this trait is harmful because it programs the body to gain weight quickly and lose weight slowly. Genes increase our risk of heart attacks, trigger asthma and allergies, cause lactose intolerance, and are related to a huge number of conditions. Genetic traits can affect our health. While some genetic defects always cause disease, most genetic traits just increase our risk of getting a disease. For example, a person may have genes that increase their risk for diabetes. However, not everyone at risk for diabetes actually develops the disease. Furthermore, even people with a high risk of diabetes can lower their risk with the right diet and exercise plan. Other genetic traits only cause illness when they are triggered by a specific environmental feature. For example, lactose intolerance is a genetic condition that causes a person who drinks milk to become ill. However, a lactose-intolerant person who never drinks milk will not have any symptoms.
External influences can affect individual genes and disrupt their function, but the majority of our defective genes are inherited from our parents. Each embryo receives half of its genes from the father and half of its genes from the mother, resulting in a new human being with some of the characteristics of each parent. The genetic defects are unfortunately passed together with these genes; for example, a genetic defect that causes heart attack may pass from the father to the child and further to the grandchild and so on, leading to passing the same disease to each generation. Whether the genetic defect is passed, however, is determined randomly, and it may be that some of the grandchildren carry the defective gene and others do not.
Thanks to the latest technologies, it is now possible to test certain genes to determine if you have genetic traits that are linked to various diseases. Based on the results of the analysis, we can develop a prevention program that significantly reduces your personal disease risk and helps you stay healthy.