{"?xml":{"@version":"1.0"},"edm:RDF":{"@xmlns:dc":"http://purl.org/dc/elements/1.1/","@xmlns:edm":"http://www.europeana.eu/schemas/edm/","@xmlns:wgs84_pos":"http://www.w3.org/2003/01/geo/wgs84_pos","@xmlns:foaf":"http://xmlns.com/foaf/0.1/","@xmlns:rdaGr2":"http://rdvocab.info/ElementsGr2","@xmlns:oai":"http://www.openarchives.org/OAI/2.0/","@xmlns:owl":"http://www.w3.org/2002/07/owl#","@xmlns:rdf":"http://www.w3.org/1999/02/22-rdf-syntax-ns#","@xmlns:ore":"http://www.openarchives.org/ore/terms/","@xmlns:skos":"http://www.w3.org/2004/02/skos/core#","@xmlns:dcterms":"http://purl.org/dc/terms/","edm:WebResource":[{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-IQXP2SEI/67fab145-d143-4bcb-96f1-078725b289a2/PDF","dcterms:extent":"798 KB"},{"@rdf:about":"http://www.dlib.si/stream/URN:NBN:SI:doc-IQXP2SEI/6a0af549-a7d7-403a-b7b8-4f5fe3572672/TEXT","dcterms:extent":"45 KB"}],"edm:TimeSpan":{"@rdf:about":"1929-2026","edm:begin":{"@xml:lang":"en","#text":"1929"},"edm:end":{"@xml:lang":"en","#text":"2026"}},"edm:ProvidedCHO":{"@rdf:about":"URN:NBN:SI:doc-IQXP2SEI","dcterms:isPartOf":[{"@rdf:resource":"https://www.dlib.si/details/urn:nbn:si:spr-a30mfzkp"},{"@xml:lang":"sl","#text":"Zdravniški vestnik"}],"dcterms:issued":"2016","dc:creator":["Geršak, Ksenija","Grželj, Jasna","Mlinarič-Raščan, Irena","Vidmar, Maša"],"dc:format":[{"@xml:lang":"sl","#text":"številka:5/6"},{"@xml:lang":"sl","#text":"letnik:85"}],"dc:identifier":["ISSN:1318-0347","COBISSID:4133489","URN:URN:NBN:SI:doc-IQXP2SEI"],"dc:language":"sl","dc:publisher":{"@xml:lang":"sl","#text":"Slovensko zdravniško društvo"},"dc:subject":[{"@xml:lang":"sl","#text":"Bolezni"},{"@xml:lang":"en","#text":"disease"},{"@xml:lang":"sl","#text":"folna kislina"},{"@xml:lang":"sl","#text":"interakcije z zdravili"},{"@xml:lang":"sl","#text":"polimorfizmi MTHFR"},{"@xml:lang":"sl","#text":"presnova folatov"},{"@xml:lang":"sl","#text":"tveganje za bolezen"}],"dcterms:temporal":{"@rdf:resource":"1929-2026"},"dc:title":{"@xml:lang":"sl","#text":"Spremenjena aktivnost encima 5,10-metilentetrahidrofolat reduktaze (MTHFR) kot dejavnik tveganja za številne bolezni| Decreased enzymatic activity of 5,10-methylenetetrahydrofolate reductase (MTHFR) as a risk factor for the development of several diseases|"},"dc:description":[{"@xml:lang":"sl","#text":"The importance of folates in human physiology is well known, as are various pathologies associated with low folate status. Folate deficiency can occur due to low dietary intake, a genetic predisposition or treatment with medicines affecting the folate status. The aim of this paper is to explore the importance of determining genetic polymorphisms, which influence the levels of biologically active folate. MTHFR is involved in the transformation of 5,10-methylene-THF to 5-methyl-THF. Polymorphisms of the MTHRF gene are associated with decreased enzymatic activity. Only 9.3 % of the population in Slovenia display full activity of the MTHFR enzyme; these subjects are non-mutated homozygotes (wild-type alleles). In contrast, the average enzymatic activity in subjects with mutated alleles is between 50 and 60 %. MTHFR polymorphism is associated with an increased risk of hyperhomocysteinemia and cardiovascular diseases, neurological disorders and various types of cancer. There is also an increased risk for congenital malformations. Folic acid food fortification was introduced in some countries in order to assure an adequate folate status in the population. However, this approach does not address the decreased activity of MTHFR. Polymorphism in the key enzymes of the folate cycle is common. Determination of the genetic predisposition is therefore plausible in the most vulnerable popultion groups, such as pregnant women and patients receiving medicines influencing the folate cycle in various ways, e.g. 5-fluorouracil, methotrexate and 6-mercaptopurine. Genotyping would allow the identification of patients at high risk for suboptimal folate status"},{"@xml:lang":"sl","#text":"Pomen folatov v fiziologiji je že dolgo znan, prav tako številne patologije, povezane z znižanim folatnim statusom. Pomanjkanje folatov pri posamezniku je lahko posledica nizkega vnosa folata, genetske zasnove posameznika ali sočasnega zdravljenja z zdravili, ki vplivajo na folatni status. Namen tega prispevka je osvetliti pomen ugotavljanja genetskih polimorfizmov, ki pomembno vplivajo na raven biološko aktivne oblike folata. V procesu pretvorbe 5,10-metilen-THF v 5-metil-THF je ključen encim MTHFR, ki je polimorfen, zato pa ima lahko zmanjšano encimsko aktivnost. V slovenski populaciji ima polno aktivnost encima MTHFR le 9,3 % posameznikov, ki so homozigoti za divji tip alelov, medtem ko je povprečna aktivnost encima pri nosilcih mutiranih alelov med 50-60 %. Prisotnost polimorfizma MTHFR predstavlja tveganje za pojav hiperhomocisteinemije in kardiovaskularnih bolezni, nevroloških bolezni, pojav raznih oblik raka, pri nosečnicah pa tudi večje tveganje za pojav okvar ploda. Za ohranjanje ustreznega folatnega statusa so v nekaterih državah uvedli dodajanje folne kisline v prehrano, vendar se je potrebno zavedati, da ta pristop ne bo odpravil pomanjkljivosti v delovanju encima MTHFR, lahko pa ublaži njihov vpliv na končni fenotip posameznika. Prisotnost polimorfizmov v ključnih genih folatnega cikla je pogosta. Zato je ugotavljanje genetske zasnove posameznika smiselno predvsem pri najbolj ranljivih skupinah prebivalstva, npr. pri nosečnicah in bolnikih, zdravljenih z zdravili, kot so 5-fluorouracil, metotreksat, 6-merkaptopurin, ki se na različne načine vpletajo v presnovno pot folatov. Genotipizacija bi prispevala k identifikaciji bolnikov, pri katerih je povečano tveganje za neustrezen folatni status in zato pomagala pri preprečenju z njim povezanih patoloških stanj"}],"edm:type":"TEXT","dc:type":[{"@xml:lang":"sl","#text":"znanstveno časopisje"},{"@xml:lang":"en","#text":"journals"},{"@rdf:resource":"http://www.wikidata.org/entity/Q361785"}]},"ore:Aggregation":{"@rdf:about":"http://www.dlib.si/?URN=URN:NBN:SI:doc-IQXP2SEI","edm:aggregatedCHO":{"@rdf:resource":"URN:NBN:SI:doc-IQXP2SEI"},"edm:isShownBy":{"@rdf:resource":"http://www.dlib.si/stream/URN:NBN:SI:doc-IQXP2SEI/67fab145-d143-4bcb-96f1-078725b289a2/PDF"},"edm:rights":{"@rdf:resource":"http://creativecommons.org/licenses/by-nc/4.0/"},"edm:provider":"Slovenian National E-content Aggregator","edm:intermediateProvider":{"@xml:lang":"en","#text":"National and University Library of Slovenia"},"edm:dataProvider":{"@xml:lang":"sl","#text":"Slovensko zdravniško društvo"},"edm:object":{"@rdf:resource":"http://www.dlib.si/streamdb/URN:NBN:SI:doc-IQXP2SEI/maxi/edm"},"edm:isShownAt":{"@rdf:resource":"http://www.dlib.si/details/URN:NBN:SI:doc-IQXP2SEI"}}}}