Genetic diseases occurred among human population from it’s beginning. Thanks to the significant progress in medicine (in developed countries) that enable curing many diseases, for example infectious and nutritional, genetic diseases became even more important. Their share has grown and they became one of the major causes of death and human tragedy.

Genetic diseases are a result of mutation in one or more genes. There are several types of them, caused by:

Familial disease is the one that is passed on from parents to their offspring (for example sickle cell anemia). Not all genetic diseases are familial. Mutation can occur for example during formation of the gametes or during development of the foetus. Health parents may have ill child (for example Down’s syndrome – trisomie of 21 chromosome). In most cases the disease is observed in the new born child, however there are some diseases that develop later in the lifetime (for example Huntington’s chorea).