title: Role of treatment-modifying MTHFR677C>T and 1298A>C polymorphisms in metformin-treated Puerto Rican patients with type-2 diabetes mellitus and peripheral neuropathy.
abstract: The study was conducted to investigate potential association between MTHFR genotypes and diabetic peripheral neuropathy (DPN) in Puerto Ricans with type-2 diabetes mellitus (T2DM) treated with metformin. The prevalence of major MTHFR polymorphisms in this cohort was also ascertained.
  
  
  
  DNAs from 89 metformin-treated patients with T2DM and DPN were genotyped using the PCR-based RFLP assay for MTHFR677C>T and 1298A>C polymorphisms. Frequency distributions of these variants in the study cohort were compared to those reported for three reference populations (HapMap project) and controls (400 newborn specimens). Chi-square (or Fischer's exact) tests and odds ratios (OR) were used to assess association with DPN susceptibility risk (patients vs. controls) and biochemical markers (wild types vs. carriers).
  
  
  
  Sixty-seven percent (67%) of participants carry at least one of these MTHFR polymorphisms. No deviations from Hardy-Weinberg equilibrium were detected. The genotype and allele frequencies showed statistically significant differences between participants and controls (p<0.0001 and p=0.03, respectively). Results suggest that 1298A>C but not 677C>T is associated with DPN susceptibility in this cohort (p=0.018). Different patterns of allelic dissimilarities are observed when comparing our cohort vs. the three parental ancestries. After sorting individuals by their carrier status, no significant associations were observed between these genetic variants (independently or combined) and any of the biochemical markers (HbA1c, folate, vitamin B12, homocysteine).
  
  
  
  Prevalence of major MTHFR variants in Puerto Rican patients with T2DM is first time ever reported. The study provides further evidence on the use of this genetic marker as an independent risk factor for DPN.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Jiménez-Ramírez
authors.forename: Liza M
authors.initials: LM
authors.lastname: Castro
authors.forename: Clarymar
authors.initials: C
authors.lastname: Ortiz
authors.forename: Jennifer
authors.initials: J
authors.lastname: Concepción
authors.forename: Jessicca Y
authors.initials: JY
authors.lastname: Renta
authors.forename: Raúl H
authors.initials: RH
authors.lastname: Morales-Borges
authors.forename: Jorge R
authors.initials: JR
authors.lastname: Miranda-Massari
authors.forename: Jorge
authors.initials: J
authors.lastname: Duconge
mesh_terms: D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy* / Q000453:epidemiology / Q000235:genetics; D003929:Diabetic Neuropathies / Q000188:drug therapy* / Q000453:epidemiology / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D005260:Female; D006630:Hispanic or Latino; D006801:Humans; D008297:Male; D008687:Metformin / Q000008:administration & dosage / Q000627:therapeutic use*; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics* / Q000378:metabolism; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*
chemical_list: D008687:Metformin; D042965:Methylenetetrahydrofolate Reductase (NADPH2)