7 January 2013 Last updated at 00:02 ET
A strong family history of seizures could increase the chances of having severe migraines, says a study in Epilepsia journal.
Scientists from Columbia University, New York, analysed 500 families containing two or more close relatives with epilepsy.
Their findings could mean that genes exist that cause both epilepsy and migraine.
Epilepsy Action said it could lead to targeted treatments.
Previous studies have shown that people with epilepsy are substantially more likely than the general population to have migraine headaches, but it was not clear whether that was due to a shared genetic cause.
The researchers found that people with three or more close relatives with a seizure disorder were more than twice as likely to experience 'migraine with aura' than patients from families with fewer individuals with seizures.
By understanding how genes work, more targeted treatments could be developed in the future.
Migraine with aura is a severe headache preceded by symptoms such as seeing flashing lights, temporary visual loss, speech problems or numbness of the face.
Dr Melodie Winawer, lead author of the study from Columbia University Medical Centre, said the findings had implications for epilepsy patients.
Read more here:
Epilepsy 'link' to migraine gene