Causes
Anencephaly results from the failure of the neural tube to close at the cepahlic end. There are a number of causes and risk factors. These include:
Genetic
Although it is thought anencephaly does not follow a direct hereditary path, it is found that there is an increase in having a second child with anencephaly if the first child has the disease. This is specifically a 3% risk. TEAD2 a transcription factor playing a role in the Hippo signalling pathway is thought to have connections with anencephaly as a decrease, tested in animals, potentially causes the disease.
Medications
Some medications such as those for the treatment of epilepsy can increase the risk of anencephaly. Women with insulin dependent diabetes also have an increased risk of having a child with a neural tube defect.
Folic acid
Folic acid is a vitamin found in fruit and vegetables as well as some cereals. It has been shown that low levels whilst the foetus is developing can cause anencephaly therefore a diet rich in folic acid is essential for a pregnant woman. 0.4mg daily is recommended for a woman of child bearing age. This can reduce the risks of neural tube defects by 40%. Women who already have a child with a neural tube defect may be prescribed an even higher dose.
Toxins
Exposure to high levels of toxins such as lead and mercury may also put the foetus at risk of developing such neural tube defects.
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