[The clinical manifestations of atherosclerosis in familial hypercholesterolemia].

AIM: To study the specific features of manifestations of atherosclerosis in Karelia dwellers with familial hypercholesterolemia (FH). SUBJECTS AND METHODS: The examination of 196 patients with FH involved laboratory tests, electrocardiography, echocardiography, triplex scanning of the arteries, exercise testing, and coronarography as indicated. Genetic examination was performed in 109 (55.6%) patients. RESULTS: The examinees' mean age was 48 +/- 2.3 years; there was a female predominance (68.7%). All the patients were found to have significant hypercholesterolemia due to elevated low-density lipoprotein levels. There was arcus lipoides corneae in 26% of cases, tendinous xanthomas in 17%, and xanthelasma palpebrarum in 34.9%. Carotid stenosis and lower extremity atherosclerosis obliterans were detected in 26.3 and 4.6%, respectively. 27.5% of the patients were diagnosed with coronary heart disease (CHD) (mean age at onset 45 years): exertional angina pectoris (10.2%), acute myocardial infarction (AMI) (14.8%), and an arrhythmic form (5.6%). 65.5% of the patients who had developed the first AMI were aged younger than 55 years. The most common site of AMI was the anterior wall of the left ventricle (55%); 51.7% of cases had transmural AMI. 24.1% of the patients sustained recurrent AMI. Complicated AMI was noted in 13.8% of cases. One third of the patients could achieve target blood lipid levels. CONCLUSION: The characteristics of the patients with FH in Karelia are a mean age of 48 years and a female predominance; the main criterion for the diagnosis of FH is significant dyslipidemia while its stigmas are rarely encountered. The specific features of CHD in the patients with FH are as follows: the age at onset is 45 years; AMI develops at the ages of less than 55 and 40 years in 65.5 and 26.3%, respectively; the rate of recurrent AMI is as high as 24%; transmural AMIs occur in 51.7% of the patients; 26.3% had signs of brachiocephalic artery stenotic lesion; 4.6% present with lower extremity atherosclerosis obliterans; one third of the patients could achieve target blood lipid levels.

[Familial hypercholesterolemia due to a new mutation in the low density lipoprotein receptor gene].

UNLABELLED: Familial hypercholesterolemia (FHC) is a genetic disorder manifest as a rise in serum cholesterol level responsible for the development ofcardiovascular diseases. AIM: To study genetic peculiarities of FHC in Kareliya. MATERIALS AND METHODS: 109 patients of the 196 ones with FHC (124 families) were subjected to genetic examination. Other parameters studied included the lipid spectrum, blood glucose level, ECG, 24 hr ECG monitoring, echocardiography, triplex scanning of brachiocephalic arteries and lower limb vessels, functional tests. Simon Broom criteria were used to diagnose FHC. RESULTS: "Definitive" FHC was diagnosed in 136 (69.4%) patients, (probable) FHC in 30.6%. The total encoding region of the low density lipoprotein receptor gene was sequenced in 109 (55.6%) patients in parallel with the search for major mutations in the APOB and PCSK9 genes. A total of 13 mutations (p.G20R, c. 192del110/ins8, c.195-196insT, p.S206R, c925- 931del17, p.S447C, p.13981, p.L426P, L511S, c.1686del18/insT, p.L646I, p.N640N, c.2191delG) were identified in low density lipoprotein receptor gene; seven of them are reported for the first time in the world. No major mutations in the APOB and PCSK9 genes were found. The new c.2191delG (p.(Val73 1Serfs*6)) mutation is characterized and its segregation with familial dyslipidemia is shown. The present case is characterized by the absence of clinical picture of coronary heart disease and the family history complicated by cerebral basin lesion. Phenotypic manifestations of atherosclerosis in FHC with gene mutations need further studies.

[A case of familial hypercholesterolemia caused by a novel mutation p. FsS65:D129X of human low density lipoprotein receptor gene].

Novel mutation p. FsS65:D129X in human low density lipoprotein receptor gene in a female patient with typical clinical symptoms of familial hypercholesterolemia is described in this paper. Segregation of this mutation with hypercholesterolemia in the family of the patient from Petrozavodsk is demonstrated.

[Genetic variants of CYP1B1 and WDR36 in the patients with primary congenital glaucoma and primary open angle glaucoma from Saint-Petersburg].

In 32 patients with primary congenital glaucoma (PCG), a search for mutations in the myocilin (MYOC), cytochrome P450B1 (CYP1B1), and WDR36 genes was performed. The Q368X mutation in myocilin gene, typical of the patients with adult-onset primary open-angle glaucoma (POAG), was not detected in the PCG patients. Screening of the CYP1B1 introns 2 and 3 for the presence of mutations in PCG patients revealed only six DNA polymorphisms, including IVS1-12ntT>C (g.3793 T>C), A119S (g.4160 G>T; GCC>TCC), G188G (g.4369 C>A; GGC>GGA), L432V (G.8131 C>G; CTG>GTG), D449D (g.8184 C>T; GAC>GAT), and N453S (g.8195 A>G; AAC>AGC) (nucleotide numbering is given in accordance with the GenBank sequence U56438). In the groups of PCG patients and donors without eye diseases, the frequencies of these variants were not statistically significantly different, pointing to the neutrality of these polymorphisms. Furthermore, the CYP1B1 polymorphism L432V, considered to be associated with POAG in some world populations, was not associated with this disease in the patients from St. Petersburg. DNA collections obtained from the POAG and PCG patients and from the control group were tested for the carriage of the worldwide distributed mutations of the WRD36 gene, D658G, R529Q, A449T, and N355S. D658G variant was found with equally low frequencies in the groups of POAG and PCG patients, as well as in the control group. Mutations A449T and R529Q were found only once each, while mutation N355S was not detected in any of the groups examined. Our results indicate that the WDR36 variants make no substantial contribution to the development of POAG and PCG in the patients from St. Petersburg and represent normal DNA polymorphism. It is likely that in most of the PCG patients from the population examined the disease is not associated with the CYP1B1 gene defects.

[Monogenic hypercholesterolemias: new genes, new drug targets].

This review is focused on recent data on structure and functions of PCSK9 proprotein convertase, a newly identified participant in cholesterol metabolism in mammalian organisms, including humans. Proprotein convertase acts as a molecular chaperone for the low density lipoprotein (LDL) receptor, targeting it to the lysosomal degradation pathway. Various mutations increasing the PCSK9 affinity toward the LDL receptor cause autosomal dominant hypercholesterolemia. In contrast, loss-of-function mutations in PCSK9 gene decrease the blood plasma cholesterol level, thus acting as a protection factor against atherosclerosis and coronary heart disease. It is supposed that pharmacological agents inhibiting the interaction between PCSK9 and LDL receptor may substantially amplify the benefits of drugs--statins and cholesterol absorption blockers--in the treatment of all types of hypercholesterolemia, including its widespread multigenic and multifactorial forms.

[Familial hypercholesterolemia in St. Petersburg: diversity of mutations argues against a strong founder effect].

Examination of low-density lipoprotein (LDL) receptor, its promoter, and major exon-intron boundaries from a sample of patients with familial hypercholesterolemia (FH) from 74 probands of St. Petersburg revealed 34 mutations and 8 widely spread polymorphisms at this locus. Only four mutations were considered silent, while the other 30 are likely associated with familial hypercholesterolemia (FH). Mutations in the LDL receptor gene, inducing the disease, were identified in 41 (55%) out of 74 families with FH. Mutation R3500Q in apolipoprotein B (APOB) gene was not detected in all probands. Therefore in the families lacking mutations hypercholesterolemia was induced by mutations in the introns of the LDL receptor gene or by other genetic factors. Nineteen mutations causing disease progression were described in St. Petersburg for the first time, while 18 of them are specific for Russia. Among Ashkenazi Jews, major mutation G197del was detected in 30% (7 out of 22) of patients with FH. In the Slavic population of St. Petersburg, no major mutations were detected. Only five mutations were identified in two families, while 24 were found in isolated families. These data are indicative of the lack of a strong founder effect for FH in the St. Petersburg population.

[Novel BRCA1 gene mutations in breast cancer patients from St. Petersburg].

Screening of patients with familial breast cancer from St. Petersburg for BRCA1 gene mutations resulted in identification of three mutations (414del3, 276delA, and A622V) and two polymorphisms (P871L and S1436S). Mutations 4146del3 and 276delA are novel, never previously described elsewhere. Deletion 2761delA produces a reading frame shift, premature protein synthesis termination and can cause predisposition for breast cancer. Deletion 414de13 does not cause a frame shift, but can result both in the disappearance of amino acid residue (D1343del) in the BRCA1 protein and in alteration of folding of the protein, entailing loss of its functional activity. Two variants of nucleotide sequence observed in the number of patients were classified as DNA polymorphisms (P871L and S1436S) rather than mutations as they were not tightly associated with the increased risk of breast cancer.

[Mutations and polymorphisms in the genes for myocilin and optineur in as the risk factors of primary open-angle glaucoma].

A collection of DNA samples obtained from primary open-angle glaucoma (POAG) patients from St. Petersburg was analyzed for single-strand conformation polymorphism (SSCP) to reveal sequence variants in exon 3 of the myocilin gene (MYOC/TIGR) and in exons 4 and 5 of the optineurin gene (OPTN), where most of the mutations revealed worldwide are located. The Q368X mutation (c. 1102 C --> T) in exon 3 of MYOC/TIGR was detected in 1.2% (2/170) of the POAG patients from St. Petersburg, i.e., with the frequency close to that observed in other world populations. Three known polymorphisms in exon 3 of MYOC/TIGR, Y347Y (c. 1041 T --> C) (12.4%), T325T (c. 975 G --> A) (0.6%), and K398R (c. 1193 A --> G) (0.6%) were also detected. No statistically significant differences in frequencies of these polymorphisms were revealed between the POAG patient and control groups. The L41L polymorphism (c. 433 G --> A) in exon 4 of OPTN was detected in 2.9% of probands and in 1% of controls. The frequency of heterozygotes for the M98K polymorphism (c. 603 T --> A) in the OPTN exon 5 was statistically significantly higher (P = 0.036; Fisher's exact test) among the POAG patients (6.5%) than among the controls (1%). In the sample examined the E50K mutation, typical of the patients with pseudonormal intraocular pressure glaucoma, was not found.

[Identification of novel missense mutation G571E, novel silent mutation H229H, nonsense mutation C74X, and four single nucleotide polymorphisms in the low-density lipoprotein receptor in patients with familial hypercholesterolemia from St. Petersburg]. / Identifikatsiia novoi missens-mutatsii G571E, novoi molchashchei mutatsii H229H, nonsens-mutatsii C74X i chetyrekh odnonukleotidnykh polimorfizmov v gene retsptora lipoproteinov nizkoi plotnosti u patsientov s semeinoi giperkholesterinemiei Sankt-Peterburga.

Novel missense mutation G571E (c.1775 G > A), novel silent mutation H229H (c.750 C > T), and nonsense mutation C74X (c.285 C > A), earlier described in Japan but unknown in Russia, were identified in the low-density lipoprotein (LDL) receptor gene in St. Petersburg familial hypercholesterolemia in patients. The analyzed group of patients was shown to be polymorphic in many positions of the LDL receptor gene, namely: c.1171 G/A, c.1773 T/C, c.2177 C/T, and c.2231 G/A.

[Four new mutations and polymorphic variants of the low density lipoprotein receptor in patients with familial hypercholesterolemia in Saint Petersburg]. / Chetyre novye mutatsii i polimorfnye varianty gena retseptora lipoproteinov nizkoi plotnosti u patsientov s semeinoi giperkholesterinemiei Sankt-Peterburga.

In a collection of DNA samples from 100 unrelated patients with clinical features of familial hypercholesterolemia (FH), a search for mutations of exons 4 and 10 of the low-density lipoprotein (LDL) receptor gene was performed using heteroduplex and single-strand conformational polymorphism (SSCP) analyses followed by sequencing of amplified DNA fragments. Four new mutations of the LDL receptor gene were identified: C146R (c.499 T > C), A130P (c.451 G > C), G128G (c.477 T > C), and C188Y (c.626 G > A). Mutation A130P was assigned to the same chromosome with allele variant 447C. Two polymorphic sites in exon 10 of the LDL receptor gene (1413G/A and 1545C/T) were found in the Russian population for the first time. Based on the data obtained, familial hypercholesterolemia was confirmed in seven patients.

[Search for frequently encountered mutations in genes predisposing to breast cancer]. / Poisk chasto vstrechaiushchikhsia mutatsii v genakh predraspolozhennosti k raku molochnoi zhelezy.

DNA of oncological patients, including Ashkenazi Jews and Slavs, living in St. Petersburg was collected, and the resultant collection was screened for three common mutations of genes BRCA1 and BRCA2 by means of heteroduplex analysis. The mutation 5382insC in exon 20 of the BRCA1 gene was found in four unrelated patients, including three Slavs and one Ashkenazi Jew, with a positive family history of breast cancer. The mutations 185delAG and 6174delT in the BRCA1 and BRCA2 genes, respectively, which are typical of Ashkenazi Jewish patients with breast cancer, were not found in the patients of either ethnicity living in St. Petersburg, although the 6174delT mutation was found in the control group of Ashkenazi Jews. A new 12-nucleotide duplication g.71741ins12nt found in intron 20 of the BRCA1 gene was described. The high frequency of the 5382insC mutation in the BRCA1 gene in patients with familial breast cancer in both St. Petersburg and Moscow indicates that Russian families with the history of breast cancer should be primarily tested for this mutation.

[The clinico-genetic aspects of familial hypercholesterolemia and their applied significance]. / Kliniko-geneticheskie aspekty semeinoi giperkholesterinemii i ikh prikladnoe znachenie.

Clinico-biochemical, genealogical evidence was compared to molecular-genetic findings on LDLP receptor gene in 4 families with a history of high blood cholesterol. It was found that members of the same family carrying the anomalous gene can demonstrate varying atherogenic shift in blood lipid fractions suggesting involvement of other endo- and exogenic factors. Molecular-genetic examination of subjects with family hypercholesterolemia discovered a family with structural derangement of the gene, two families with spot defects and a family in which the proband's hypercholesterolemia seemed unrelated to changes in the gene, but probably related to the gene controlling synthesis of apoB-protein.

[Molecular heterogeneity of familial hypercholesterolemia in the St. Petersburg population]. / Molekuliarnaia geterogennost' semeinoi giperkholesterinemii v populiatsii zhitelei Sankt-Peterburga.

Inheritance of Taq I, BstE II, and Nco I restriction fragment length polymorphisms (RFLP) in three families from St. Petersburg with familial hypercholesterolemia (FH) was studied. In two of these families, polymorphic markers of the low density lipoprotein receptor (LDLR) gene cosegregated with the disease. This data confirmed FH diagnosis based on the analysis of blood plasma lipid levels. Three different RFLP haplotypes were associated with the disease, suggesting the presence of at least three point mutations in the LDLR gene in the population studied, i.e., suggesting molecular heterogeneity of FH in the St. Petersburg population.

[A multiexon deletion in the human low density lipoprotein receptor gene as a reason for familial hypercholesterolemia]. / Mul'tiékzonnaia deletsiia v gene retseptora lipoproteinov nizkoi plotnosti cheloveka kak prichina semeinoi giperkholesterinemii.

Inheritance of Taq I, BstE II, and Nco I restriction fragment length polymorphisms (RFLP) in three families from St. Petersburg with familial hypercholesterolemia (FH) was studied. In two of these families, polymorphic markers of the low density lipoprotein receptor (LDLR) gene cosegregated with the disease. This data confirmed FH diagnosis based on the analysis of blood plasma lipid levels. Three different RFLP haplotypes were associated with the disease, suggesting the presence of at least three point mutations in the LDLR gene in the population studied, i.e., suggesting molecular heterogeneity of FH in the St. Petersburg population.