Table 1

 MTHFR genotyping: published literature

AuthorObjective/study designnPolymorphismsTreatment regimensResults
BMT, bone marrow transplant; CML, chronic myelogenous leukaemia; DB, double blind; MTHFR, methylene tetrahydrofolate reductase; MTX, methotrexate; PC, placebo controlled; RA, rheumatoid arthritis.7–9
Ulrich et al9C677T modification of response to MTX Retrospective220 CML BMTTT = 16%CT = 42% CC = 42%MTX intravenous ×4 doses Folate/folic acid unknownTT genotype associated with ↑ toxicity (mucositis, ↓ platelet recovery)
Van Ede et al7Relationship between C677T and efficacy and toxicity of MTX236 RATT = 8% CT = 40% CC = 52%MTX MTX and folate MTX and folic acidT/T and T/C genotypes associated with ↑ toxicity and MTX discontinuation
Prospective, DB, PC
Urano et al8C677T and A1298T association with MTX efficacy and toxicity Retrospective106 RATT = 17% CT = 50% CC = 33% AC = 27% CC = 3%MTX doses variable(MTX treatment had been discontinued in some patients) Folic acid not given in most casesPrevalence of polymorphisms was reported to be associated with both MTX efficacy and toxicity T at C677T and C at A1298C—toxicity