[Medico-genetic counselling of the relatives of patients with type I diabetes mellitus].

Population-genetic surveys show that for the relatives of patients with type I diabetes mellitus (the 1st degree of kinship) a risk of developing the same type of diabetes is 2-5%. Tables of repeated risk of developing diabetes mellitus (DM) of type I for persons with a different number of relatives affected by this type of DM were calculated on the basis of analysis of 2000 family histories of DM patients (a random sampling). A risk of developing this disease is in direct correlation with the number of sick and healthy relatives and their age. The presence of patients with type II DM in a family does not influence the risk of developing type I DM. Risk assessments are of prognostic rather than diagnostic value. The effectiveness of medico-genetic counselling can be increased with the help of various genetic markers, associated with type I DM. Risk assessment must lay the basis of a follow-up of persons with aggravated heredity by investigating immunological, hormonal and metabolic derangements in them.