MedGen

Spinocerebellar ataxia type 6 (SCA6) is characterized by adult-onset, slowly progressive cerebellar ataxia, dysarthria, and nystagmus. The age of onset ranges from 19 to 73 years; mean age of onset is between 43 and 52 years. Initial symptoms are gait unsteadiness, stumbling, and imbalance (in ~90%) and dysarthria (in ~10%). Eventually all persons have gait ataxia, upper-limb incoordination, intention tremor, and dysarthria. Dysphagia and choking are common. Visual disturbances may result from diplopia, difficulty fixating on moving objects, horizontal gaze-evoked nystagmus, and vertical nystagmus. Hyperreflexia and extensor plantar responses occur in up to 40%-50%. Basal ganglia signs, including dystonia and blepharospasm, occur in up to 25%. Mentation is generally preserved. [from GeneReviews]

For a phenotypic description and discussion of genetic heterogeneity of migraine headaches, see MGR1 (157300). [from OMIM]

Any migraine disorder in which the cause of the disease is a mutation in the KCNK18 gene. [from MONDO]

An inherited susceptibility or predisposition to developing migraines without aura. [from MONDO]

Advanced sleep phase syndrome is characterized by very early sleep onset and offset (summary by Jones et al., 1999). For a discussion of genetic heterogeneity of advanced sleep phase syndrome, see FASPS1 (604348). [from OMIM]

Repeated headache attacks lasting 4-72 h fulfilling at least two of the following criteria [from HPO]