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Borissov K, Markova R, Elenkov I, Kostov K, Savov A, Kremensky I, Argirova R. Genetic Polymorphism of the Chemokine Co-Receptors CCR5, CXCR4 and CCR2 in Bulgarians Living with HIV. BIOTECHNOL BIOTEC EQ 2014. [DOI: 10.1080/13102818.2007.10817468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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Bogdanova N, Baleva M, Kremensky I, Markoff A. The annexin A5 protective shield model revisited: inherited carriage of the M2/ANXA5 haplotype in placenta as a predisposing factor for the development of obstetric antiphospholipid antibodies. Lupus 2012; 21:796-8. [PMID: 22635237 DOI: 10.1177/0961203312438235] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This concise review summarizes the role of reduced ANXA5 expression through carriage of the M2/ANXA5 haplotype as a predisposing factor for various thrombophilia related obstetric complications. A revised ANXA5 'protective shield' model is emphasized, where decreased coverage resulting of M2 carriage at placental villi could lead directly to the observed pathology and on the other hand through exposing of antiphospholipid antigenic determinants, to the development of antiphospholipid antibodies (aPL). The aPL then can further disrupt the ANXA5 protective shield. Available and prospective evidence for this revised model is discussed. Conclusions are made about the diagnostic implications of M2 carriage and possible therapeutic strategies with anticoagulants, proven successful in obstetric antiphospholipid syndrome (APS) treatment.
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Affiliation(s)
- N Bogdanova
- Institute of Human Genetics, UKM and University of Muenster, Germany
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Vlaykova T, Mitkova A, Stancheva G, Kadiyska T, Gulubova M, Yovchev Y, Cirovski G, Chilingirov P, Damyanov D, Kremensky I, Mitev V, Kaneva R. Microsatellite instability and promoter hypermethylation of MLH1 and MSH2 in patients with sporadic colorectal cancer. J BUON 2011; 16:265-273. [PMID: 21766496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
PURPOSE Inactivation of the genes involved in DNA mismatch repair (MMR) is associated with microsatellite instability (MSI) and loss of heterozygosity (LOH). The aim of the current study was to assess the presence of MSI and promoter hypermethylation of MLH1 and MSH2 in Bulgarian PATIENTS WITH SPORADIC COLORECTAL CANCER (CRC) AND TO ANALYZE THEIR POSSIBLE EFFECT ON THE DEVELOPMENT, PROGRESSION AND PROGNOSIS OF THE DISEASE. METHODS We examined MSI in 126 patients with sporadic CRC and the methylation status of the MLH1 and MSH2 promoter regions in the cases with MSI/LOH by using a panel of 5 microsatellite markers (BAT26, D5S346, D18S35, D2S123 and FGA) and methyl-specific PCR (MSP) of bisulfite converted DNA. RESULTS MSI/LOH was found in 36 (28.6%) patients. Among them, 30 were analyzed for promoter hypermethylation of MLH1 and we detected hypermethylation in 15 (50%) of them, whereas promoter hypermethylation of MSH2 was observed only in one case. The presence of MSI/LOH was associated with younger age (p=0.002), more advanced stage (III/IV stage) (p=0.029), lower degree of differentiation (p=0.001), and right-sided tumor localization (p=0.0002), but not with overall survival (log rank, p=0.566). CONCLUSION Our data suggest that sporadic CRCs with MSI/LOH are more aggressive, develop earlier and progress faster to more advanced stage. The most frequent cause of failure of DNA MMR system appeared to be the hypermethylation of CpG islands of the promoter region of MLH1, whereas the methylation of MSH2 was a rare event.
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Affiliation(s)
- T Vlaykova
- Department of Chemistry and Biochemistry, Medical Faculty, Trakia University, Stara Zagora, Bulgaria.
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Gucev ZS, Tasic V, Sinigerska I, Kremensky I, Tincheva R, Pop-Jordanova N, Danilovski D, Hofer D, Paschke E. Hunter syndrome (Muccopolysaccharridosis Type II) in Macedonia and Bulgaria. Pril (Makedon Akad Nauk Umet Odd Med Nauki) 2011; 32:187-198. [PMID: 22286622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
BACKGROUND Mucopolysaccharidosis II (MPS II) is caused by a deficiency of iduronate-2-sulfatase (IDS; EC 3.1.6.13). METHODS AND RESULTS We describe 11 boys from Bulgaria and Macedonia detected in the period from 1998 to 2008. The mean age at diagnosis was 4.77+/-1.29 years. All children were severely retarded: IQ ranged from 34-80, and they all had coarse faces and hepatomegaly. In addition, splenomegaly was found in 81.81% patients, dysostosis in 45.45%, kyphosis in 27.27%, deafness in 18.08%, growth below the third percentile in 45.45%, growth below the parental target height in all patients, stiff joints in 56.56% and hypertrophic myocardiopathy in 18.18% children. Two patients died at the age of 11 and 35 years. Plasma iduronate-2-sulfatase was low in all probands and normal in parents and relatives. Two new mutations were discovered: p.K236N (c.708G>C) in a child with a moderately severe phenotype, and p.Q80K (c.238C>A) which resulted in a severe phenotype and early death at the age of 11 years. Heterozygote carriers of the pathogenic allele were 29 female relatives. The calculated incidence rate for MPS II in Macedonia (censuses 1994 and 2002, children under 14 years: 483,923 and 426,280) and Bulgaria (censuses 1992 and 2006, children under 14 years: 1 126, 598 and 1,077,020) are 0.36 and 0.46 respectively, while the calculated prevalence rate are 3.6 and 4.6 per 1,000,000 boys (aged 0-14 years). Correlating phenotype and genotype remains a complex endeavour. CONCLUSIONS We report calculated incidence and prevalence rates in two South Eastern European countries, and 2 novel genetic alterations correlated with their phenotypes.
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Affiliation(s)
- Z S Gucev
- University Children's Hospital, Medical School, Skopje, R. Macedonia
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Bichev S, Hristova S, Slavova Y, Vajarova R, Kachakova D, Kaneva R, Kremensky I. 109 Implementation of qPCR and sequencing for KRAS and EGFR mutation detection in Bulgarian patients with colorectal and lung cancer. EJC Suppl 2010. [DOI: 10.1016/s1359-6349(10)70917-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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6
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Suls A, Velizarova R, Yordanova I, Deprez L, Van Dyck T, Wauters J, Guergueltcheva V, Claes LRF, Kremensky I, Jordanova A, De Jonghe P. Four generations of epilepsy caused by an inherited microdeletion of the SCN1A gene. Neurology 2010; 75:72-6. [DOI: 10.1212/wnl.0b013e3181e62088] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Konstantinova D, Kadiyska T, Sokolova V, Kaneva R, Mirchev M, Savov A, Aleksandrova A, Nedin D, Kostadinov E, Damyanov D, Kremensky I, Mitev V. CHEK2 I157T and colorectal cancer in Bulgaria. J BUON 2010; 15:314-317. [PMID: 20658728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
PURPOSE Germline variants of the CHEK2 gene have been shown to act as low-penetrance cancer susceptibility alleles for a wide range of human malignancies. CHEK2 I157T has particularly been linked to colorectal cancer (CRC) risk. We aimed at establishing the population frequency and contribution of this variant to colorectal carcinogenesis in Bulgaria. METHODS We have genotyped 802 population controls and 343 CRC patients from Bulgaria for the CHEK2 I157T variant. RESULTS Heterozygous were 9 of 343 patients (2.62%, odds ratio/OR=1.0, 95% confidence interval/CI = 0.42 - 2.33, p=0.99% and 21 of 802 controls (2.62%). Higher frequencies were found among patients with multiple polyposis (2/40, 5%, p=0.28) and the rarer mucinous histology (1/11, 9.09%, p= 0.26). CONCLUSION We conclude that CHEK2 I157T is not relevant for CRC risk in Bulgaria, but studies on a larger scale might help evaluate its possible significance in respect to disease characteristics.
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Affiliation(s)
- D Konstantinova
- Molecular Medicine Center, Medical University, Sofia and University Hospital of Obstetrics and Gynaecology "Maichin Dom", 2 Zdrave Street, 1431 Sofia, Bulgaria.
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Stoykova V, Vagarova R, Markov D, Kremensky I, Ivanov S. [Low PAPP-A levels between 11 and 13(+6) weeks of gestation and the risk of preeclampsia]. Akush Ginekol (Sofiia) 2010; 49:19-25. [PMID: 21427871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
PAPP-A is one of the 2 biochemical markers of the first trimester Down syndrome serum screening. In Bulgaria this screening was first performed in 2006. The threshold values for evaluation of the risk of development of preeclampsia used by the researchers vary in a wide range. Nevertheless in the last several years the most used value is 0.4 MoM. The aim of represented study is evaluate the low PAPP-A levels as a marker for development of preeclampsia alone, or in combination with some risk factors. The data of 194 singleton pregnancies that underwent a first trimester Down syndrome screening between January 2008 and June 2009 had been analyzed. Twenty three patients (11.6%) developed preeclampsia, of which 8 required delivery before 34th gw. The control group includes 134 women who had term deliveries of healthy babies. Nine out of 23 (39%) patients with preeclampsia, 5 out of 8 (62.5%) patients with early onset preeclampsia and 42 out of 134 (30.4%) controls had PAPP-A levels below 0.4 MoM. These levels are associated with relative risk for development of preeclampsia of 1.5 times. Low PAPP-A levels in the first trimester were associated with a low prognostic value for development of preeclampsia and early preeclampsia before 34th gw. When low PAPP-A levels are added to the maternal age and especially results of Doppler evaluation of the uterine arteries significant prognostic value improvement was observed.
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Gucev ZS, Tasic V, Pop-Jordanova N, Kirovski I, Stomnaroska O, Martinova M, Jancevska A, Kremensky I, Sinigerska I. Type I Gaucher disease (GDI) in three siblings: enzyme replacement treatment (ERT) required. Pril (Makedon Akad Nauk Umet Odd Med Nauki) 2009; 30:233-240. [PMID: 19736544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
(Full text is available at http://www.manu.edu.mk/prilozi). This is a family of three children, born to healthy Macedonian parents after uneventful pregnancies and delivery. The index child was an eight-year-old girl admitted for abdominal discomfort and distension: the spleen was 14cm below the costal margin (BCM), the liver 8cm BCM. No bone pain or pathology was reported. There was mild pancytopaenia (hemoglobin 11.2 gm/L; WBC counts 4.6 x 10;3; platelets 70 x 10;3). Liver function tests, renal ultrasound, bone scan, and a chest radiograph were within normal limits. Bone marrow analysis in this child and her two brothers (11 and 6.5 years old) revealed Gaucher cells. Both brothers had only mild anaemia, but the older brother had been splenectomized prior to diagnosis of GD1. Enzyme analysis revealed low activity (2.59, 1.62, and 2.55 nmol/h/mg protein, respectively); plasma chitotriosidase levels were also elevated. Genetic testing revealed homozygosity for the N370S/N370S mutation in all three siblings. In the absence of available enzyme replacement treatment (ERT), the girl was splenectomized. Removing an important immune organ (the spleen) introduces further risk for the patients. In addition, this does not solve the bone involvement characteristic for GD. ERT should be introduced for all GD1 patients in Macedonia. Key words: Gaucher disease, N370S mutation, siblings, enzyme replacement therapy.
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Affiliation(s)
- Z S Gucev
- University Children's Diseases Clinic, Faculty of Medicine, Skopje, R. Macedonia.
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Mitkova A, Dodova R, Vlahova A, Dikov T, Sedloev T, Jonkov A, Kremensky I, Christova S, Kaneva R. Mutation screening of BRCA1 exon 11 in Bulgarian breast cancer families. EJC Suppl 2008. [DOI: 10.1016/s1359-6349(08)71566-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Konstantinova D, Kadiyska T, Kaneva R, Guseva V, Tosheva E, Dimitrov B, Dimitrov R, Doganov N, Kremensky I, Mitev V. CHEK2 I157T is not associated with an increased risk of endometrial cancer in Bulgarian patients. EJC Suppl 2008. [DOI: 10.1016/s1359-6349(08)71565-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Encheva E, Lackov T, Yordanova I, Savov A, Kaneva R, Zahariev Z, Sultanov B, Kremensky I, Hadjieva T. Association analysis of XRCC1 and XRCC3 polymorphisms with normal tissue reactions after pelvic irradiation. EJC Suppl 2008. [DOI: 10.1016/s1359-6349(08)71759-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Mihaylova V, Todorov T, Jelev H, Cherninkova S, Raycheva M, Savov A, Kremensky I, Tournev I. Wilson’s disease in two consecutive generations in a Bulgarian Roma family. J Neurol 2007; 254:1462-3. [PMID: 17694349 DOI: 10.1007/s00415-007-0564-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Revised: 12/17/2006] [Accepted: 01/11/2007] [Indexed: 11/25/2022]
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Ivanova N, Löfgren A, Tournev I, Rousev R, Andreeva A, Jordanova A, Georgieva V, Deconinck T, Timmerman V, Kremensky I, De Jonghe P, Mitev V. Spastin gene mutations in Bulgarian patients with hereditary spastic paraplegia. Clin Genet 2007; 70:490-5. [PMID: 17100993 DOI: 10.1111/j.1399-0004.2006.00705.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hereditary spastic paraplegia (HSP) is an extremely heterogeneous group of neurodegenerative disorders affecting the longest axons in the central nervous system. The most common genetic form accounting for about 40% of the autosomal-dominant HSP (ADHSP) cases is spastin gene, SPG4. We performed mutation screening of the spastin gene on 36 unrelated HSP patients from three different ethnic groups (Bulgarian, Turks and Gypsies) and found four new mutations and one already reported. The phenotype-genotype correlations in Bulgarian SPG4 patients showed a great difference in the age at disease onset between patients with missense mutations and those harboring deletions and splice-site mutations. Our study is the first to present corroborative clinical data in favor of the general hypothesis that the clinical course of the disease is related to the type of the spastin mutation. The clinical and genealogical findings in Bulgarian SPG4 patients suggest that a positive family history for inheritance as an autosomal-dominant trait is a strong indication for spastin mutation screening.
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Affiliation(s)
- N Ivanova
- Department of Chemistry and Biochemistry, Medical University, Sofia, Bulgaria.
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Todorov T, Savov A, Mihaylova V, Buettner J, Koseva O, Krustev Z, Jelev H, Tournev I, Penkov V, Konstantinova D, Tankova L, Tzolova N, Kremensky I, Schmidt H. Ethnic specific background of mutations in Bulgarian patients with Wilson disease. Genet Couns 2007; 18:445-450. [PMID: 18286826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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Todorov T, Savov A, Jelev H, Panteleeva E, Konstantinova D, Krustev Z, Mihaylova V, Tournev I, Tankova L, Tzolova N, Kremensky I. Spectrum of mutations in the Wilson disease gene (ATP7B) in the Bulgarian population. Clin Genet 2005; 68:474-6. [PMID: 16207219 DOI: 10.1111/j.1399-0004.2005.00516.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Mehrabian S, Jordanova A, Rademakers R, Raycheva M, Cruts M, Kremensky I, Van Broeckhoven C, Traykov L. P1-6 Nouvelle mutation sur le gène de la PSEN1 chez une patiente atteinte de la maladie d’Alzheimer à début précoce. Rev Neurol (Paris) 2005. [DOI: 10.1016/s0035-3787(05)85322-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Georgieva B, Todorova A, Tournev I, Mitev V, Kremensky I. C283Y gamma-sarcoglycan gene mutation in the Bulgarian Roma (Gypsy) population: prevalence study and carrier screening in a high-risk community. Clin Genet 2004; 66:467-72. [PMID: 15479193 DOI: 10.1111/j.1399-0004.2004.00335.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Limb-girdle muscular dystrophy type 2C (LGMD2C) is caused by mutations in the gamma-sarcoglycan gene where a founder Gypsy mutation C283Y was detected. The Bulgarian Gypsy LGMD2C patients, as the Gypsy patients from other countries, were found to be homozygous for this mutation. Considering the large number of Gypsies in Bulgaria and the high percent of consanguinity and endogamy a raised carrier frequency of the C283Y mutation was expected especially in North-Eastern Bulgaria where most of the patients originate from. Here, we present the precise geographic distribution of the C283Y mutation in the general Roma population from the whole Bulgarian territory by determining the carrier frequency of the mutation in dry blood newborn samples. Our results show that the geographic distribution of this founder mutation and the disease are not geographically restricted only among Gypsies from North-Eastern Bulgaria. We stress upon the regions with detected high carrier and/or disease frequency and upon the results from the performed carrier screening on volunteers in one of these regions. The ongoing carrier-screening programs in isolated Gypsy groups would be of a great benefit for the genetic prophylaxis of the disease. Such regions should be with priority in the Bulgarian healthcare system for performing a carrier-screening program.
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Affiliation(s)
- B Georgieva
- Laboratory of Molecular Pathology, University Hospital of Obstetrics and Gynecology, Sofia Medical University, 2 Zdrave Str, Bulgaria.
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Jordanova A, De Jonghe P, Boerkoel CF, Takashima H, De Vriendt E, Ceuterick C, Martin JJ, Butler IJ, Mancias P, Papasozomenos SC, Terespolsky D, Potocki L, Brown CW, Shy M, Rita DA, Tournev I, Kremensky I, Lupski JR, Timmerman V. Mutations in the neurofilament light chain gene (NEFL) cause early onset severe Charcot-Marie-Tooth disease. Brain 2003; 126:590-7. [PMID: 12566280 DOI: 10.1093/brain/awg059] [Citation(s) in RCA: 198] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Neurofilament light chain polypeptide (NEFL) is one of the most abundant cytoskeletal components of the neuron. Mutations in the NEFL gene were recently reported as a cause for autosomal dominant Charcot-Marie-Tooth type 2E (CMT2E) linked to chromosome 8p21. In order to investigate the frequency and phenotypic consequences of NEFL mutations, we screened 323 patients with CMT or related peripheral neuropathies. We detected six disease associated missense mutations and one 3-bp in-frame deletion clustered in functionally defined domains of the NEFL protein. Patients have an early onset and often a severe clinical phenotype. Electrophysiological examination shows moderately to severely slowed nerve conduction velocities. We report the first nerve biopsy of a CMT patient with a de novo missense mutation in NEFL, and found an axonal pathology with axonal regeneration clusters and onion bulb formations. Our findings provide further evidence that the clinical variation observed in CMT depends on the gene mutated and the specific type of mutation, and we also suggest that NEFL mutations need to be considered in the molecular evaluation of patients with sporadic or dominantly inherited CMT.
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Affiliation(s)
- A Jordanova
- Molecular Genetics Department, Flanders Interuniversity Institute for Biotechnology, University of Antwerp, Belgium
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Abstract
A total of 280 unrelated males from the three largest population groups in Bulgaria: Bulgarians, Bulgarian Turks and Gypsies, were analyzed for seven Y-chromosome STRs (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392 and DYS393). Comparison of the allele frequency distributions revealed significant differences between the three ethnic groups which were confirmed with haplotype analysis. This permits us to suggest that population differentiation should be taken into account in forensic case analysis and paternity testing in Bulgaria.
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Affiliation(s)
- B Zaharova
- Laboratory of Molecular Pathology, University Hospital of Obstetrics and Gynaecology, 2 Zdrave St, 1431 Sofia, Bulgaria.
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Abstract
All three types of autosomal recessive spinal muscular atrophy map to chromosome region 5q13. Recent reports suggest that they are associated with deletions of two adjacent genes: SMN and NAIP. Here we report the first deletion analysis of Bulgarian SMA families. Homozygous deletion of exons 7 and 8 of the SMN gene were found in 85% of our patients, but the NAIP gene (exons 5 and 6) was deleted in only 26% of patients. To our knowledge, these frequencies are some of the lowest reported so far. The NAIP gene was deleted predominantly in severely affected patients (type I), while in the group with milder types SMA only deletions of the SMN gene were detected. Our phenotype-genotype correlation study confirmed that larger deletions are associated with more severe clinical course. The Bulgarian data support the thesis that the telomeric SMN gene could play a major role in determining SMA, while the NAIP or the centromeric SMN copy have a modifying effect on the phenotype.
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Affiliation(s)
- A Jordanova
- Laboratory of Molecular Pathology, University Hospital of Obstetrics and Gynecology, Medical University, Sofia, Bulgaria
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Abstract
Sarcoglycanopathies, affecting the dystrophin-associated sarcoglycan (SG) complex, are a heterogeneous group of neuromuscular disorders. A subgroup of these disorders, limb-girdle muscular dystrophy type 2C (LGMD2C) is an autosomal recessive disorder, clinically manifested as an early onset, severe Duchenne-like muscular dystrophy. LGMD2C is caused by mutations in the gamma-SG gene, localized on 13q12. Recently, a number of mutations have been described in that gene, among which C283Y, a "private" Gypsy mutation (eight codons before the 3' end of the gene) is detected. In this article, we report on a single-strand conformation polymorphism (SSCP) method for fast C283Y mutation detection, using direct dry blood spot amplification. The method permits a large number of samples to be easily screened. To check heterozygote carriers of C283Y mutation among Gypsy population in Bulgaria, the SSCP analysis was applied on 400 Gypsy newborns from northeast Bulgaria. Our results show 2.25% of heterozygosity, which means that 1 in 50 Gypsies carries the mutation. Moreover, new SSCP migration patterns were detected that revealed two polymorphisms still unavailable in the literature. One of these changes was 984G-->A, leading to substitution of conserved serine at position 287 with asparagine and the second one is 1049C-->G at the 3' UTR (untranslated region). The present data could help the understanding the role of these sequences for the protein function.
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Affiliation(s)
- A Todorova
- Laboratory of Molecular Pathology, University Hospital of Obstetrics and Gynaecology, Sofia, Bulgaria
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Abstract
Studies of the sensitivity of SSCP analysis usually have been performed under conditions contrary to the rules of quality control trials and have produced widely different results. We have performed a blind trial of the sensitivity of SSCP analysis for the detection of mutations in fragments up to 500 bp in length under a fixed single set of electrophoretic conditions. The mutation detection rate was 84%. In addition, we have identified a second mutation in nine samples. All these mutations are polymorphisms, including a novel polymorphism 1248 + 52T/C first reported in the present work.
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Affiliation(s)
- A Jordanova
- Laboratory of Molecular Pathology, University Hospital of Obstetrics, Sofia, Bulgaria
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24
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Kalaydjieva L, Perez-Lezaun A, Angelicheva D, Onengut S, Dye D, Bosshard NU, Jordanova A, Savov A, Yanakiev P, Kremensky I, Radeva B, Hallmayer J, Markov A, Nedkova V, Tournev I, Aneva L, Gitzelmann R. A founder mutation in the GK1 gene is responsible for galactokinase deficiency in Roma (Gypsies). Am J Hum Genet 1999; 65:1299-307. [PMID: 10521295 PMCID: PMC1288282 DOI: 10.1086/302611] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Galactokinase deficiency is an inborn error in the first step of galactose metabolism. Its major clinical manifestation is the development of cataracts in the first weeks of life. It has also been suggested that carriers of the deficiency are predisposed to presenile cataracts developing at age 20-50 years. Newborn screening data suggest that the gene frequency is very low worldwide but is higher among the Roma in Europe. Since the cloning of the galactokinase gene (GK1) in 1995, only two disease-causing mutations, both confined to single families, have been identified. Here we present the results of a study of six affected Romani families from Bulgaria, where index patients with galactokinase deficiency have been detected by the mass screening. Genetic linkage mapping placed the disease locus on 17q, and haplotype analysis revealed a small conserved region of homozygosity. Using radiation hybrid mapping, we have shown that GK1 is located in this region. The founder Romani mutation identified in this study is a single nucleotide substitution in GK1 resulting in the replacement of the conserved proline residue at amino acid position 28 with threonine (P28T). The P28T carrier rate in this endogamous population is approximately 5%, suggesting that the mutation may be an important cause of early childhood blindness in countries with a sizeable Roma minority.
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Affiliation(s)
- L Kalaydjieva
- Centre for Human Genetics, Edith Cowan University, Joondalup Campus, Perth WA 6027, Australia.
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Kremensky I, Jankova S, Bochukova E, Uzunova M, Litvinenko I, Jordanova A. Molecular study of spinal muscular atrophy patients with hybrid genes in Bulgaria. J Inherit Metab Dis 1999; 22:322-6. [PMID: 10384397 DOI: 10.1023/a:1005512306358] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- I Kremensky
- Laboratory of Molecular Pathology, Sofia Medical University, Bulgaria
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Demirov D, Sarafian V, Kremensky I, Ganev V. Evidence for protein splicing in the endoplasmic reticulum-Golgi intermediate compartment. Biochim Biophys Acta 1999; 1448:507-11. [PMID: 9990302 DOI: 10.1016/s0167-4889(98)00158-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We present evidence that the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) is a site for protein splicing of cathepsin C: (i) maturation of the enzyme in COS 7 cells is a two-step process starting within the ERGIC, and (ii) the intermediately processed polypeptide retains both termini of the proenzyme and lacks an internal fragment.
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Affiliation(s)
- D Demirov
- Department of Chemistry and Biochemistry, Medical University, Sofia, Bulgaria
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Kaneva R, Milanova V, Onchev G, Stoyanova V, Chakarova CH, Nikolova A, Hallmayer J, Belemezova M, Milenska T, Kirov G, Kremensky I, Kalaydjieva L, Jablensky A. A linkage study of affective disorders in two Bulgarian Gypsy families: results for candidate regions on chromosomes 18 and 21. Psychiatr Genet 1998; 8:245-9. [PMID: 9861644 DOI: 10.1097/00041444-199808040-00008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- R Kaneva
- Laboratory of Molecular Pathology, University Obstetrics Hospital, Sofia, Bulgaria.
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Affiliation(s)
- D Demirov
- Department of Chemistry and Biochemistry, Department of Molecular Pathology, Medical University of Sofia, Sofia 1431, Bulgaria
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Tanaka K, Gregersen N, Ribes A, Kim J, Kølvraa S, Winter V, Eiberg H, Martinez G, Deufel T, Leifert B, Santer R, François B, Pronicka E, László A, Kmoch S, Kremensky I, Kalaydjicva L, Ozalp I, Ito M. A survey of the newborn populations in Belgium, Germany, Poland, Czech Republic, Hungary, Bulgaria, Spain, Turkey, and Japan for the G985 variant allele with haplotype analysis at the medium chain Acyl-CoA dehydrogenase gene locus: clinical and evolutionary consideration. Pediatr Res 1997; 41:201-9. [PMID: 9029639 DOI: 10.1203/00006450-199702000-00008] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Medium chain acyl-CoA dehydrogenase (MCAD) deficiency is an inborn error of fatty acid metabolism. It is one of the most frequent genetic metabolic disorders among Caucasian children. The G985 allele represented 90% of all the variant alleles of the MCAD gene in an extensive series of retrospective studies. To study the distribution of the G985 allele, newborn blood samples from the following countries were tested; 3000 from Germany (1/116). 1000 each from Belgium (1/77). Poland (1/98), Czech Republic (1/240). Hungary (1/168), Bulgaria (1/91), Spain (1/141). Turkey (1/216), and 500 from Japan (none). The frequency is shown in parentheses. The haplotype of G985 alleles in 1 homozygote and 57 heterozygote samples were then analyzed using two intragenic MCAD gene polymorphisms (Iaq1 and GT-repeat). The result indicated that only 1 of the 10 known haplotypes was associated with the G985 mutation, suggesting that G985 was derived originally from a single ancestral source. We made a compilation of the G985 frequencies in these countries and those in nine other European countries studied previously. The G985 distribution was high in the area stretching from Russia to Bulgaria in the east and in all northern countries in western and middle Europe, but low in the southern part of western and middle Europe. The incidence among ethnic Basques appeared to be low. This distribution pattern and the fact that all G985 alleles belong to a single haplotype suggest that G985 mutation occurred later than the delta F508 mutation of the CFTR, possibly in the neolithic or in a later period, and was brought into Europe by IndoEuropean-speaking people. The panEuropean distribution of the G985 allele, including Slavic countries from which patients with MCAD deficiency have rarely been detected, indicates the importance of raising the level of awareness of this disease.
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Affiliation(s)
- K Tanaka
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
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Markoff A, Savov A, Vladimirov V, Bogdanova N, Kremensky I, Ganev V. Optimization of single-strand conformation polymorphism analysis in the presence of polyethylene glycol. Clin Chem 1997; 43:30-3. [PMID: 8990218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We report optimization of single-strand conformation polymorphism (SSCP) analysis in the presence of polyethylene glycol. The protocol developed separates single-strand conformers in a much shorter time (1-3 h) than conventional SSCP protocols and broadens the applicability of SSCP analysis from 150 to as much as 500 bp of DNA by different percentages of GC content present. We conclude that addition of polyethylene glycol helps improve the differential separation of conformers and, in combination with high-resolution polyacrylamide gel electrophoresis, offers an alternative to previous SSCP analysis protocols. This protocol should be very useful for clinical applications in routine detection of mutations as well as for research purposes.
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Affiliation(s)
- A Markoff
- Laboratory of Molecular Biology and Genetics, Department of Chemistry and Biochemistry, Medical University Sofia, Bulgaria.
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Todoroya A, Bronzova J, Miorin M, Rosa M, Kremensky I, Danieli GA. Mutation analysis in Duchenne and Becker muscular dystrophy patients from Bulgaria shows a peculiar distribution of breakpoints by intron. Am J Med Genet 1996; 65:40-3. [PMID: 8914739 DOI: 10.1002/(sici)1096-8628(19961002)65:1<40::aid-ajmg6>3.0.co;2-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
For the first time in Bulgaria, a deletion/duplication screening was performed on a group of 84 unrelated Duchenne/Becker muscular dystrophy patients, and the breakpoint distribution in the dystrophin gene was analyzed. Intragenic deletions were detected in 67.8% of patients, and intragenic duplications in 2.4%. A peculiar distribution of deletion breakpoints was found. Only 13.2% of the deletion breakpoints fell in the "classical" hot spot in intron 44, whereas the majority (> 54%) were located within the segment encompassing introns 45-51, which includes intron 50, the richest in breakpoints (16%) in the Bulgarian sample. Comparison with data from Greece and Turkey points at the probable existence of a deletion hot spot within intron 50, which might be a characteristic of populations of the Balkan region.
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Affiliation(s)
- A Todoroya
- Laboratory of Molecular Pathology, University Hospital of Obstetrics and Gynecology, Sofia, Bulgaria
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Savov A, Angelicheva D, Jordanova A, Kremensky I, Kalaydjieva L. 2176insC: a novel mutation in exon 13 of the cystic fibrosis gene. Hum Hered 1996; 46:166-7. [PMID: 8860011 DOI: 10.1159/000154346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Affiliation(s)
- A Savov
- Laboratory of Molecular Pathology, University Hospital of Obstetrics, Sofia, Bulgaria
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Abstract
Living under a totalitarian regime has many effects on the structure, way of thinking, and relations in a society. However, it is the impact on neonatal genetic screening that we discuss in this paper. Genetic screening functions at the interface between health services and society at large. Being involved for over a decade in setting up the Bulgarian PKU screening programme, we have had to deal with ways and attitudes which may be difficult for the western mind to grasp. Yet comprehension is very much needed in the new world we are trying to create.
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Affiliation(s)
- L Kalaydjieva
- Laboratory of Molecular Pathology, Institute of Obstetrics, Sofia, Bulgaria
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Kalaydjieva L, Dworniczak B, Kremensky I, Koprivarova K, Radeva B, Milusheva R, Aulehla-Scholz C, Horst J. Heterogeneity of mutations in Bulgarian phenylketonuria haplotype 1 and 4 alleles. Clin Genet 1992; 41:123-8. [PMID: 1563085 DOI: 10.1111/j.1399-0004.1992.tb03647.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A study of Bulgarian patients with classical PKU demonstrated that haplotypes 1 and 4 carry a significant number of rare molecular defects resulting from independent mutational events. Differences in mutations associated with these common haplotypes exist even between populations which share a common major PKU mutation. Some amino acid substitutions, previously reported to lead to mild phenylalanine hydroxylase deficiency, were detected in the present study in compound heterozygotes with severe PKU. These findings preclude carrier testing and hyperphenylalaninemia typing by genomic analysis at least in the heterogeneous Bulgarian population.
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Affiliation(s)
- L Kalaydjieva
- Laboratory of Molecular Pathology, Medical Academy, Sofia, Bulgaria
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Dworniczak B, Kalaydjieva L, Aulehla-Scholz C, Ullrich K, Kremensky I, Radeva B, Horst J. Recurrent nonsense mutation in exon 7 of the phenylalanine hydroxylase gene. Hum Genet 1991; 87:731-3. [PMID: 1682234 DOI: 10.1007/bf00201735] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A new mutation (CGA to TGA) in codon 261 of exon 7 of the phenylalanine hydroxylase gene transforms Arg261 to a stop codon in two unrelated patients of German and Turkish origin. The different ethnic backgrounds and the different polymorphic characteristics of the two mutant alleles suggest an independent origin of the mutation. This is the second defect detected in codon 261 of the phenylalanine hydroxylase gene, a codon that thus appears to be a mutation hot spot.
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Affiliation(s)
- B Dworniczak
- Institut für Humangenetik der Universität, Münster, Federal Republic of Germany
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Kalaydjieva L, Dworniczak B, Aulehla-Scholz C, Kremensky I, Bronzova J, Eigel A, Horst J. Classical phenylketonuria in Bulgaria: RFLP haplotypes and frequency of the major mutations. J Med Genet 1990; 27:742-5. [PMID: 1981599 PMCID: PMC1017277 DOI: 10.1136/jmg.27.12.742] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
RFLP haplotypes and common mutations in the phenylalanine hydroxylase gene have been studied in a group of 29 Bulgarian PKU families. Haplotype distribution differs from that in other European populations, with a predominance of haplotypes 2 and 6 and a total absence of haplotype 3. The amino acid substitution in codon 408 is the most frequent molecular defect. The splicing defect in intron 12 is not found in Bulgarian PKU patients. Testing for three mutations, reported to be common among haplotype 1 and 4 alleles, has shown that they occur less frequently in Bulgarian PKU patients. Screening with five pairs of allele specific oligonucleotides failed to show the mutation in 59% of the patients. These findings add to the evidence that PKU is heterogeneous and that significant interpopulation differences exist. At present, DNA data cannot be used as an aid in early clinical classification and prognosis of hyperphenylalaninaemia in Bulgaria.
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Affiliation(s)
- L Kalaydjieva
- Laboratory of Molecular Pathology, Medical Academy, Sofia, Bulgaria
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Hlebarova M, Ruscova S, Kremensky I, Tsvetkov D, Kamenov V. Enzymes and cytomorphological sperm alterations in some diseases of the male reproductive system. Int Urol Nephrol 1980; 12:361-5. [PMID: 6132894 DOI: 10.1007/bf02082474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
In this work the alterations of some acrosomal enzymes and gamma-GT were studied in diseases of the male genital tract. Thirty-two patients with vascular diseases, seven with inflammatory diseases and twenty-four controls were investigated. In all patients the sperm morphology was studied and the following enzymes were assayed: beta-glucuronidase, beta-galactosidase, beta-glucosidase and gamma-GT. In all patients with vascular and inflammatory diseases we found severe hypokinesis and decreased number of spermatozoa. The activity of all four enzymes in both pathological groups was decreased in comparison with the controls, and this decrease was significant for all enzymes in males with vascular diseases and for beta-galactosidase and beta-glucosidase in cases with inflammatory diseases. Our data show that the decrease of spermatozoal count was accompanied by a decreased enzyme activity. The role of decreased sperm plasma enzyme activity, the decreased production of spermatozoa and quantitative changes in structure and acrosome enzyme content are discussed.
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