It is considered the most common human genetic disease. If the patient inherits the gene that causes the disease from both the father and the mother, then the course of the disease is severe and life expectancy decreases dramatically (most patients die from a heart attack or blood-stroke before the age of 30, including high infant mortality). If the “sick” gene is inherited from only one of the parents, the disease progresses more slowly, but still the risk of early cardiovascular death increases by 20 times. At first, the disease is undetected: only a significant increase in the level of cholesterol in the blood (low density fraction) is observed. Then there are symptoms of cholesterol deposition under the skin in the tendons, eyes and symptoms of cardiovascular complications due to deposits of cholesterol on the walls of blood vessels and on the heart valves (including the development of ischemic heart disease, leading to myocardial infarction). With this disease there is no diet that could lead to a lower level of low-density cholesterol. Nevertheless, there is and effective medical treatment, it is critical to learn about it as early as possible.