Genetics and migraine
The role genetics play in migraine
Genetics play a big role in migraine. This means that it is often inherited in families. It is estimated that up to 60% of the reason people get migraine is because of their genes. These genes make people more sensitive to changes in their environment such as lifestyle factors and triggers that can bring on an attack.
What is the role of genes in migraine?
In most cases a single gene defect or mutation is unlikely to cause migraine. It is more likely to develop from several different genes all coming together. However, even if you have the genes that increase your chances, you still might not get migraine.
This is probably because migraine is also influenced by the environment, such as by stress or hormonal changes. Conditions such as migraine, where genes and environment interact are referred to as complex genetic disorders.
Types of genetic factors
In the more common types of migraine, there isn’t a clear-cut form of inheritance where specific genes will lead to migraine. It is thought that a number of genes are involved and there’s susceptibility in those genes. This is referred to as an ‘association’ meaning if you have a particular gene variation, then you’re more likely to suffer from the disorder.
Some other types of migraine are caused by mutations in specific genes. If you have those mutations you will have a specific type of migraine – they don’t just increase the likelihood of having it, they cause it.
There are three identified causal genes found in Hemiplegic Migraine – CACNA1A, ATP1A2 and SCN1A. Hemiplegic migraine is a rare type of migraine with aura caused by mutations in these genes. These genes influence how ion channels function, which has an impact on nerve activity.
Here the variations occur in either a calcium channel, an ATPase, or a sodium channel gene. As a result, people who have mutations in one of these three ion channel genes, can get the disorder and it is passed on to subsequent generations.
Why are ion channel genes so important for migraine?
Genes involved in moving salts are called ion channel or transporter genes. They are important because they can determine how easily activated our nerves are and how they might react when stimulated. In recent years, it has become very clear that migraine is mainly a disorder of the nervous system.
What is TRESK?
In 2010, a gene called TRESK was found to be directly linked to migraine. This was an important step in working out why some people are predisposed to getting this condition.
Based on the idea that ion channels and transporters are important for migraine, some studies have specifically examined these genes in people with migraine.
TRESK was identified in this kind of study. A defective mutation was found in the gene for TRESK in one person having migraine with aura. TRESK is abundant in the main sensory relay station of the brain – the trigeminal ganglion.
The trigeminal ganglion is a very important site just outside the brain and is thought to have an important role in migraine pain.
Do I have mutations in the TRESK gene?
It is very unlikely because the mutation so far has only been found in one family despite our looking at the DNA of many other people with migraine. It is not unusual for these types of mutations to be rare and it is likely that the vast majority of people with migraine will not have a mutation in the TRESK gene.
What can be done?
Having the inherited tendency to have migraine does not mean that you will have migraine attacks. For the common types of migraine (with and without aura), being able to identify things like triggers and lifestyle factors is a useful first step. Being able to modify those, where possible, is going to affect how often and how severe the attacks occur.
If you or your family is possibly affected by a causal gene mutation (such as familial hemiplegic migraine), a neurologist who specialises in genetic disorders may be able to do the specific blood tests to confirm the diagnosis. This can help with treatment. Speak to your GP or Neurologist for more information.
There is a range of migraine treatments and these should be explored with your doctor or specialist. Treatments today can be very effective to better manage the condition and reduce the impact of symptoms.