Mutations to the methylenetetrahydrofolate reductase, or MTHFR, gene cause health problems such as homocystinuria, anencephaly and spina bifida but have no known benefits, according to the Genetics Home Reference. The MTHFR gene is essential in amino acid and protein production.
Homocystinuria is a suite of around 40 MTHFR gene mutations that causes faulty production of the methylenetetrahydrofolate reductase enzyme, says the Genetics Home Reference. Some mutations result in the formation of a nonfunctional form of the enzyme, while others cause it to be inactive. Researchers are still studying the effects of homocystinuria on the body.
Anencephaly is a neural tube defect the occurs during brain and spinal cord formation, reports the Genetics Home Reference. Those affected have poorly formed or absent skull bones and sometimes are missing significant areas of their brain. Spina bifida, another neural tube disorder, causes the vertebrae to not form completely. This means that parts of the spinal cord are exposed, sometimes leading to nerve damage.
Mutations of the MTHFR gene are also implicated in a variety of other health problems, says the Genetics Home Reference. MTHFR mutations are a potential risk factor for stroke, heart disease, hypertension, glaucoma, mental illness and even some types of cancer. There is also a possible link between MTHFR mutations and cleft palate.