Abstract: Objective To investigate the relationship between polymorphism in methylenetetra-hydrofolate reductase (MTHFR ) and acute cerebral infarction (CI), observe the variation regular of fasting plasma homocysteine (Hcy) level.Methods Using Homocysteine Microplate STE Assay to examine the fasting plasma homocysteine level of 28 CI patients during their initial stage (flaring up between 1 to 3 days) and later stage (flaring up 10 to 15 days) of acute period and 27 healthy controls. The presence of the MTHFR genetic type was determined by polymerase chain reaction (PCR) assay and subsequent restriction enzyme digestion.Results There was no significant difference among the three MTHFR genotypes in distributed frequency of the CI group, normal controls and the 677 allelic gene (P>0.05). The discrepancy of Hcy level in various kinds of genotypes: heterozygote mutation and homozygoto mutation were much higher than wild type (P<0.01). Homozygoto mutation was higher than heterozygote mutation, but there was no significant difference between them (P>0.05). The high homocysteine of group CI during the acute early stage were found out more frequent than normal control (P<0.05). There was no significant difference of fasting plasma Hcy level between the initial stage and later stage of CI group which were in acute period (P>0.05), both of the Results were higher than normal control (P<0.01). There was no significant difference among the Hcy level of various genetypes in CI group during the initial stage and later stage of acute period (P<0.05).Conclusion MTHFR gene C677T mutation is one of the cause of high homocystinemia, while it dose not lead to CI directly. High Hcy level is the independent risk factor of CI, but has no concern to the course of acute CI.

Key words: homocystine, methylenetetra-hydrofolate reductase (MTHFR), polymorphism, cerebral infarction