title: Methylenetetrahydrofolate reductase genetic polymorphisms in patients with cataract.
abstract: OBJECTIVE
  Hyperhomocysteinemia is commonly associated with polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene. The level of homocysteine can be lowered by dietary intake of folate. A protective effect of folate supplementation has been reported against cataract. Here we investigate MTHFR polymorphisms in human cataract.
  
  
  METHODS
  Retrospective case-control association study.
  
  
  METHODS
  Patients with nuclear (n = 77), cortical (n = 155), posterior subcapsular (n = 119), and mixed (n = 151) cataract, and 187 controls were analyzed for the MTHFR 677C-->T and 1298A-->C polymorphisms using minisequencing technique.
  
  
  RESULTS
  The wild-type MTHFR 677CC/1298AA genotype was strongly overrepresented among cataract cases (P = .003). This effect was most pronounced in the mixed cataract group (P < .001). Hyperhomocysteinemia-associated genotypes had similar frequencies in cataract and control groups.
  
  
  CONCLUSIONS
  The previously reported protective effect of folate against cataract is not due to overrepresentation of hyperhomocysteinemia-associated MTHFR genotypes. Instead, the strong predominance of wild-type MTHFR in cataract may suggest impaired DNA synthesis as a cataractogenic factor.
authors.affiliation: Institute of Clinical Neuroscience, Section of Ophthalmology, Sahlgrenska University Hospital, Göteborg University, Mölndal, Sweden. madeleine.zetterberg@anatcell.gu.se
authors.forename: Madeleine
authors.initials: M
authors.lastname: Zetterberg
authors.forename: Gunnar
authors.initials: G
authors.lastname: Tasa
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Prince
authors.forename: Mona
authors.initials: M
authors.lastname: Palmér
authors.forename: Erkki
authors.initials: E
authors.lastname: Juronen
authors.forename: Siiri
authors.initials: S
authors.lastname: Veromann
authors.forename: Pait
authors.initials: P
authors.lastname: Teesalu
authors.forename: Jan-Olof
authors.initials: JO
authors.lastname: Karlsson
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002386:Cataract / Q000201:enzymology / Q000235:genetics*; D004252:DNA Mutational Analysis; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D020138:Hyperhomocysteinemia / Q000235:genetics; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D011110:Polymorphism, Genetic; D012189:Retrospective Studies; D017422:Sequence Analysis, DNA
chemical_list: D042965:Methylenetetrahydrofolate Reductase (NADPH2)