Can Migraine Skip a Generation?

[Anonymous]

Can Migraine Skip a Generation?

[Genetic Counselor]

Yes, migraine can appear to skip a generation. For example, a grandmother may experience migraine, her daughter may never develop it, and her granddaughter may begin having migraine attacks during adolescence or adulthood.

However, this pattern does not necessarily mean that migraine has followed a specific inheritance pattern. The explanation depends on the type of migraine and the genetic factors involved.
Most migraine cases are classified as complex or multifactorial conditions. This means that susceptibility is influenced by multiple genetic variations, each contributing a relatively small amount to overall risk. These variations can be inherited in different combinations across generations.

A person may inherit some migraine-associated genetic variations without developing noticeable symptoms. Their children may subsequently inherit a combination of genetic variations that increases their susceptibility. Consequently, migraine may appear to skip one or more generations, even though genetic susceptibility has been passed through the family.
Another explanation is variable expression. This occurs when people with similar genetic susceptibility experience different symptoms or levels of severity. One family member may have frequent migraine attacks, another may experience occasional headaches, and another may have no recognised symptoms.

It is also possible that migraine in an older relative was never formally diagnosed. Some individuals may have experienced recurrent headaches, nausea, visual disturbances, or sensitivity to light without recognising these symptoms as migraine. This can make the family history appear less consistent than it actually is.
However, it is important to distinguish common migraine from rare inherited conditions.

One example is familial hemiplegic migraine, a rare subtype associated with migraine attacks involving temporary motor weakness. Certain forms are linked to pathogenic variants in genes such as CACNA1A, ATP1A2, and SCN1A. Depending on the specific condition, inheritance may follow an autosomal dominant pattern.
In autosomal dominant conditions, a person with a disease-causing variant has a 50% chance of transmitting that variant to each child. However, inheriting the variant does not always guarantee that symptoms will develop. This phenomenon is known as reduced penetrance. Differences in symptom severity among affected individuals are described as variable expressivity.
These genetic principles can explain why some rare inherited neurological conditions appear to skip generations.

Nevertheless, common migraine should not automatically be interpreted as an autosomal dominant disorder simply because several family members are affected.
A detailed family history, including the age of onset, headache characteristics, neurological symptoms, and affected relatives across generations, can help a healthcare professional determine whether specialist genetic assessment may be appropriate.

[Author]

Posts