title: MTHFR gene polymorphism and age of onset of schizophrenia and bipolar disorder.
abstract: OBJECTIVE
  Several studies with contradictory results from different cultures about association of methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism in schizophrenia and bipolar disorders. Little is known about this association in Arab culture and Egypt. So the present study aimed to assess the association of MTHFR C677T polymorphism in bipolar disorder (BD) and schizophrenia in comparison to control group. The association between MTHFR C677T polymorphism and the age at onset in schizophrenia or BD was also studied.
  
  
  METHODS
  Polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) were used to examine the genotype and allele frequencies of MTHFR C677T polymorphism in 149 healthy subjects and 134 bipolar and 103 schizophrenia patients.
  
  
  RESULTS
  In BD and schizophrenia, there was a higher prevalence of MTHFR C677T polymorphism than healthy subjects. Earlier age at onset was found in patients with BD, carrying one copy of the T allele or CT genotypes but not in patients with schizophrenia.
  
  
  CONCLUSIONS
  The present findings suggest that the MTHFR C677T polymorphisms are likely to be associated with the risk of developing BD and schizophrenia and influence the age at onset of BD but not the age at onset of schizophrenia.
authors.affiliation: Psychiatric Department, Faculty of Medicine, Mansoura University, 45 El Thorah Street, El-Refaay Tower, Mansoura 35111, Egypt.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: El-Hadidy
authors.affiliation: Medical Biochemistry Department, Faculty of Medicine, Mansoura University, Mansoura 35111, Egypt.
authors.forename: Hanaa M
authors.initials: HM
authors.lastname: Abdeen
authors.affiliation: Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura 35111, Egypt.
authors.forename: Sherin M
authors.initials: SM
authors.lastname: Abd El-Aziz
authors.affiliation: Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura 35111, Egypt.
authors.forename: Mohammad
authors.identifier: 0000-0003-4112-116X
authors.initials: M
authors.lastname: Al-Harrass
mesh_terms: D000328:Adult; D017668:Age of Onset; D001714:Bipolar Disorder / Q000235:genetics* / Q000473:pathology; D004534:Egypt; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D012559:Schizophrenia / Q000235:genetics* / Q000473:pathology
chemical_list: C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)
references.citation: Neurosci Lett. 2006 Jun 12;400(3):267-71
references.pmid: 16545905
references.citation: Am J Med Genet B Neuropsychiatr Genet. 2012 Dec;159B(8):981-6
references.pmid: 23076983
references.citation: Asian J Psychiatr. 2012 Jun;5(2):144-9
references.pmid: 22813657
references.citation: Nutr Rev. 2008 May;66(5):250-5
references.pmid: 18454811
references.citation: Prog Neuropsychopharmacol Biol Psychiatry. 2005 Sep;29(7):1133-9
references.pmid: 16111796
references.citation: Psychiatr Genet. 2006 Jun;16(3):105-15
references.pmid: 16691128
references.citation: Schizophr Res. 2010 Dec;124(1-3):216-22
references.pmid: 20692813
references.citation: Mol Psychiatry. 2002;7(2):123-4
references.pmid: 11840300
references.citation: Am J Med Genet B Neuropsychiatr Genet. 2008 Sep 5;147B(6):976-82
references.pmid: 18165967
references.citation: J Psychopharmacol. 2005 Jan;19(1):59-65
references.pmid: 15671130
references.citation: Nat Genet. 2008 Sep;40(9):1056-8
references.pmid: 18711365
references.citation: Prog Neuropsychopharmacol Biol Psychiatry. 2008 Jul 1;32(5):1331-7
references.pmid: 18513846
references.citation: Nat Genet. 2013 Oct;45(10):1150-9
references.pmid: 23974872
references.citation: Cell Mol Life Sci. 2007 Jun;64(12):1531-8
references.pmid: 17458502
references.citation: Nat Genet. 2011 Sep 18;43(10):977-83
references.pmid: 21926972
references.citation: Am J Med Genet B Neuropsychiatr Genet. 2005 May 5;135B(1):2-4
references.pmid: 15729744
references.citation: J Inherit Metab Dis. 1996;19(5):589-94
references.pmid: 8892013
references.citation: Am J Med Genet B Neuropsychiatr Genet. 2010 Oct 5;153B(7):1362-3; author reply 1361
references.pmid: 20593383
references.citation: Psychiatr Genet. 2004 Dec;14(4):227-31
references.pmid: 15564899
references.citation: Cell Mol Biol (Noisy-le-grand). 2011 Sep 27;57 Suppl:OL1558-66
references.pmid: 21955385
references.citation: J Korean Med Sci. 2011 Oct;26(10):1356-63
references.pmid: 22022190
references.citation: Am J Med Genet B Neuropsychiatr Genet. 2010 Oct 5;153B(7):1298-304
references.pmid: 20552676
references.citation: Brain Behav Immun. 2011 Nov;25(8):1530-43
references.pmid: 21185933
references.citation: Drugs. 1994 Aug;48(2):137-52
references.pmid: 7527320
references.citation: Am J Med Genet B Neuropsychiatr Genet. 2010 Jan 5;153B(1):298-302
references.pmid: 19350535
references.citation: Iran J Psychiatry. 2011 Winter;6(1):1-6
references.pmid: 22952513
references.citation: Nat Struct Biol. 1999 Apr;6(4):359-65
references.pmid: 10201405
references.citation: Nat Genet. 2011 Sep 18;43(10):969-76
references.pmid: 21926974
references.citation: Am J Med Genet B Neuropsychiatr Genet. 2011 Mar;156(2):215-24
references.pmid: 21302350
references.citation: Neurosci Lett. 2009 Jan 2;449(1):48-51
references.pmid: 18983889
references.citation: Am J Med Genet B Neuropsychiatr Genet. 2010 Mar 5;153B(2):610-618
references.pmid: 19746410
references.citation: Trends Genet. 2004 Aug;20(8):350-8
references.pmid: 15262407
references.citation: CNS Spectr. 2010 Apr;15(4):220-30
references.pmid: 20414171
references.citation: Mol Psychiatry. 2009 Nov;14(11):992-1003
references.pmid: 19851280
references.citation: Neuropsychobiology. 2014;69(2):107-11
references.pmid: 24577139
references.citation: Schizophr Res. 2007 May;92(1-3):181-8
references.pmid: 17344026
references.citation: J Biol Chem. 1953 Sep;204(1):403-16
references.pmid: 13084611
references.citation: JAMA. 1996 Jul 24-31;276(4):293-9
references.pmid: 8656541
references.citation: Biol Psychiatry. 2000 Feb 1;47(3):210-20
references.pmid: 10682218
references.citation: Am J Epidemiol. 2007 Jan 1;165(1):1-13
references.pmid: 17074966
references.citation: Br Med J. 1967 Dec 2;4(5578):512-6
references.pmid: 6065984
references.citation: Dev Psychobiol. 2010 May;52(4):331-42
references.pmid: 20127889
references.citation: Trends Mol Med. 2009 Dec;15(12):562-70
references.pmid: 19896901
references.citation: Lipids Health Dis. 2010 Oct 27;9:123
references.pmid: 20977771
references.citation: Mol Psychiatry. 2006 Feb;11(2):143-9
references.pmid: 16172608
references.citation: Nutr Res Rev. 2006 Jun;19(1):117-36
references.pmid: 19079880