Familial hypercholesterolemia in Karelia: occurrence, spreading, clinical, and genetic peculiarities, therapy (10 years management experience)

Familial hypercholesterolemia (FH) is an inherited metabolic disease resulting in specific elevation of the low-density lipoprotein (LDL) in blood plasma. The purpose of the research was to study genetic and clinical features of FH in Karelia. Totally 196 patients with FH from 124 Karelian families were examined (69 % were female). The average age of the researched patients was 48 ± 2.3 years old. Genetic tests were performed in 109 patients (55,6 %). In all patients blood plasma lipid spectrum, glucose plasma concentration, thyroid hormones levels were measured. Electrocardiography, Holter's monitoring of electrocardiography, echocardiography, triplex scanning of carotid arteries and vessels of lower extremities together with stress tests were performed. Clinical diagnosis of FH was set according to Simon Broom criteria. The main clinical features of FH in Karelia include the following: FH patients frequently have additional non lipid risk factors (arterial hypertension in 64,5 %, smoking in 34 %, obesity in 48 %). The presence of FH stigmata was not frequent (corneal arcus in 26 %, tendon xantomas in 17,3 %, xantelasma in 34 %). Atherosclerosis was diagnosed in 117 patients (59,7 %), among them - ischemic heart disease was diagnosed in 27,5 % (more than half of them had myocardial infarction), atherosclerosis of brain vessels - in 26,5 % (stroke in 6 %), atherosclerosis of lower extremities - in 4,6 %, multifocal atherosclerosis - in 21 %. Manifestations of ischemic heart disease usually develop in patients of 45 years old, myocardial infarction - in 45,4 years old, brain atherosclerosis - in 56 years old. The targeted lipid level was obtained in 27 % of patients with FH. These patients were treated with statins. Special genetic features of the disease characteristic of Karelia include the follwing: lack of evident "founder" effect; specific Finnish mutations not typical for Karelia, new LDL receptor mutations, namely c.192del110/ins8, c.195-196insT, c.2191delG, S206R. R3500Q mutation of the APOB gene was not found in the sample of 109 persons at all. In FH patients from Karelia some clinical and genetic specific features were observed.