The MTHFR C677T mutation is known to result a decrease in the enzymes function and is associated with several disease states. While these are undesirable, the mutation is widespread across many populations worldwide. One of these is the Mediterranean region, which has one of the highest frequencies of the MTHFR C677T mutation worldwide. Interestingly, it also has an endemic of malaria. Therefore, Meadows et al (2014) examined mice for a link between a mutation in the MTHFR C677T gene and the prevalence of malaria, hypothesizing the high rates of C677T polymorphisms in the region could be occurring in order to play a role in protecting against malarial infection.
The authors studied different groups of mice with varying levels of the MTHFR C677T mutation who had been infected with malaria. Overall, mice infected with malaria that also had the C677T mutation were found to survive longer, and also had increased levels of immune cells and proteins.
Overall, the authors suggested a mild mutation in the MTHFR C677T gene protects against malarial infection, which could have led to the high prevalence of this mutation occurring in human populations.