MIGRAINE WITHOUT AURA AND MIGRAINE WITH AURA ARE INHERITED DISORDERS

The familial occurrence and mode of inheritance were analysed in famil ies with migraine without aura (MO) and migraine with aura (MA). The p robands were found among 4000 persons from the general population. All persons with MA were included as probands, and an equivalent number o f probands with MO was selected as a random sample among those with MO . Spouses and first-degree relatives were blindly interviewed. All int erviews were performed by one neurological research fellow. The distin ct familial patterns indicate that MO and MA have a different aetiolog y. Compared with the general population, the first-degree relatives of probands with MO had a 1.9-fold increased risk of MO while spouses ha d a 1.5-fold increased risk of MO, indicating that both genetic and en vironmental factors are important in MO. The first-degree relatives of probands with MA had a four-fold increased risk of MA while spouses h ad no increased risk of MA, indicating that MA is determined largely b y genetic factors. The complex segregation analysis indicated that bot h MO and MA have multifactorial inheritance without generational diffe rence.