Familial hypercholesterolemia (FH) is the most common autosomal dominant disorder. It is characterized by a de crease in LDL cholesterol catabolism and an early clinical manifestation of atherosclerotic vessel damage. The aim of the MedPed (Make early diagnosis to Prevent early deaths) project is an early diagnosis of FH patients in order to profit from early treat ment and prevent cardiov ascular events. Till November 30, 2016 The Czech National MedPed Database has registered 7,001 FH patients from 5,223 different families that is 17.4 % of expected patients in the Czech Republic considering 1:250 FH prevalence. The improvement in diagnostic accuracy, patient cooperation and above all familial cascade screening is enabled by FH mutation detection using the modern technology of next-generation sequencing. FH still remain undiagnosed even though the Czech Republic is on e of the most successful countries with respect to FH detection. The opportunities of international collaboration and experience sharing within international programs (e.g. EAS FHSC, ScreenPro FH etc.) will improve the detection of FH patients in the futur e and enable even more accessible and accurate genetic diagnostics., M. Vrablík, M. Vaclová, L. Tichý, V. Soška, V. Bláha, L. Fajkusová, R. Češka, M. Šatný, T. Freiberger., and Obsahuje bibliografii
The aim of the study was to ascertain whether the A-204C polymorphism in the cholesterol 7alfa-hydroxylase (CYP7A1) gene plays any role in determining LDL-cholesterol (LDL-C) concentration responsiveness to a high-fat diet. The concentrations of total cholesterol and LDL-cholesterol were measured in eleven healthy men (age: 30.9±3.2 years; BMI: 24.9±2.7 kg/m2) who were homozygous for either the -204A or -204C allele, after 3 weeks on a low-fat (LF) diet and 3 weeks on a high-fat (HF) diet. During both dietary regimens, the isocaloric amount of food was provided to volunteers; LF diet contained 22 % of energy as a fat and 2.2 mg of cholesterol/kg of body weight a day, HF diet 40 % of fat and 9.7 mg of cholesterol/kg of body weight a day. In six subjects homozygous for the -204C allele, the concentrations of cholesterol and LDL-cholesterol were significantly higher on HF than on LF diet (cholesterol: 4.62 vs. 4.00 mmol/l, p<0.05; LDL-C: 2.15 vs. 1.63 mmol/l, p<0.01, respectively); no significant change was observed in five subjects homozygous for the -204A allele. There were no other differences in lipid and lipoprotein-lipid concentrations. Therefore, the polymorphism in the cholesterol 7α-hydroxylase promotor region seems to be involved in the determination of cholesterol and LDL-C responsiveness to a dietary fat challenge.
The treatment of hypercholesterolemia with bile acid (BA)
sequestrants results in upregulation of BA synthesis through the
classical pathway initiated by cholesterol 7α-hydroxylase (CYP7A1). To characterize the detailed dynamics of serum lipid and BA concentrations and the BA synthesis rate in response to treatment with BA sequestrants and to determine whether the -203A/C promoter polymorphism of the CYP7A1 encoding gene (CYP7A1) affects such a response, this pilot study was carried out in healthy men (8
h omozygous for the -203A allele and 8 homozygous for the -203C allele of CYP7A1). The subjects were treated for 28 days with colesevelam
and blood was drawn for analysis before and on days 1, 3, 7, 14 and 28 of treatment. The response of lipids, BA, fibroblast growth factor-19 (FGF19) and 7α-hydroxy-4-cholesten-3-one (C4) to colesevelam did not differ between carriers of -203A and -203C alleles; their data were then aggregated for further analysis. Colesevelam treatment caused immediate suppression of FGF19 concentration and a fivefold increase in CYP7A1 activity, as assessed from C4 concentration, followed by a 17% decrease in LDL-cholesterol. Although total plasma BA concentrations were not affected, the ratio of cholic acid/total BA rose from 0.25±0.10 to 0.44±0.16 during treatment at the expense of decreases in chenodeoxycholic and deoxycholic acid.
Nedávné studie ukázaly, že prevalence familiární hypercholesterolemie (FH) je přibližně dvojnásobná oproti dřívějším předpokladům a onemocnění tak postihuje přibližně jednoho z 250 jedinců obecné populace. Jedná se tedy o nejčastější vrozené metabolické onemocnění vůbec. V důsledku geneticky podmíněné poruchy v metabolizmu LDL-cholesterolu dochází k jeho hromadění v cirkulaci a ve tkáních, což vede předčasnému rozvoji aterosklerózy. Neléčení jedinci mohou mít infarkt myokardu ve 3. nebo 4. dekádě života, až v jedné třetině případů s fatálním koncem. Onemocnění je celosvětově nedostatečně diagnostikováno a léčeno. V České republice běží již od roku 1998 projekt MedPed, který se soustředí na včasnou diagnostiku FH s cílem zahájit léčbu co nejdříve, a snížit tak u postižených jedinců riziko předčasné klinické manifestace ischemické choroby srdeční a předčasného úmrtí. Důležitým bodem projektu je kaskádovitý screening mezi příbuznými pacientů s FH. V celonárodní databázi evidujeme již více než 6 350 pacientů s FH, což představuje asi 16 % z očekávaného počtu pacientů v České republice. Takový záchyt nás řadí mezi nejúspěšnější země na světě, ale i s ohledem na příchod nových terapeutických možností zůstává detekce a včasné zahájení léčby nemocných s FH v centru naší pozornosti. Klíčová slova: familiární hypercholesterolemie – kardiovaskulární riziko – kaskádovitý screening – MedPed, Recent studies have revealed the prevalence of familial hypercholesterolemia (FH) is approximately twice higher than previously estimated and, thus, the disease affects one in 250 persons from the general population. Therefore FH remains the most frequent inherited metabolic disorder. Due to the genetic defect LDL-cholesterol accumulates both in the plasma and tissues leading to premature and accelerated atherosclerosis. Untreated patients with FH might suffer from myocardial infarction in the third or fourth decade, one third of these events being fatal. The disease is underdiagnosed and undertreated worldwide. In the Czech Republic the MedPed project focused on early diagnosis and initiation of proper treatment of FH aiming at lowering of the above mentioned risks was initiated in 1998. A crucial part of the project is so called cascade screening among the relatives of identified FH probands. There are 6,350 registered FH subjects in the nationwide registry, which represents 16% of the expected number of FH patients in the Czech Republic. This result of screening efforts ranks among the top countries in the world, however, also in spite of the recent expansion of FH treatment options early detection and initiation of treatment of FH remains in the centre of our attention. Key words: familial hypercholesterolemia – cardiovascular risk – cascade screening – MedPed, and Tomáš Freiberger, Michal Vrablík