title: The MTHFR C677T polymorphism is associated with depressive episodes in patients from Northern Ireland.
abstract: Low plasma folate and its derivatives have been linked with depressive disorders in studies dating back over 30 years. A thermolabile variant (677C>T) of the enzyme 5,10-methylenetetrahydrofolate reductase (MTHFR) is associated with low serum folate. The present study aimed to explore whether the thermolabile variant of MTHFR is associated with a vulnerability to depressive episodes. MTHFR C677T genotype frequencies in a cohort of patients (mean age 48 years) with depressive disorder (n = 100) were compared with those in age- and sex-matched controls. Serum levels of folate, homocysteine and vitamin B(12) were also compared between groups. The thermolabile variant of MTHFR was significantly more common in the group with a history of depressive disorder (P= 0.03). Serum levels of folate, homocysteine and vitamin B(12) did not differ significantly between groups. A MTHFR C677T genotype is associated with increased risk of depressive episodes in this homogenous patient population.
authors.affiliation: Department of Mental Health, Queen's University Belfast, Belfast BT9 7BL, UK. chriskelly@bch.n-i.nhs.uk
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Kelly
authors.forename: Anne P
authors.initials: AP
authors.lastname: McDonnell
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Johnston
authors.forename: Ciaran
authors.initials: C
authors.lastname: Mulholland
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Cooper
authors.forename: Dorothy
authors.initials: D
authors.lastname: McMaster
authors.forename: Alun
authors.initials: A
authors.lastname: Evans
authors.forename: Alexander S
authors.initials: AS
authors.lastname: Whitehead
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003866:Depressive Disorder / Q000453:epidemiology / Q000235:genetics* / Q000523:psychology*; D005260:Female; D005492:Folic Acid / Q000097:blood; D005787:Gene Frequency; D005838:Genotype; D006711:Homocystine / Q000097:blood; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D008297:Male; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D014805:Vitamin B 12 / Q000097:blood
chemical_list: D006711:Homocystine; D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2); D014805:Vitamin B 12