Mutations in the SCN1A gene are associated with a variety of epilepsy syndromes and more recently with familial hemiplegic migraine. The spectrum of phenotypes can be quite broad even within the same family and with the same mutation. Here we describe a child with intractable myoclonic epilepsy and autism spectrum disorder who carries an inherited mutation in SCN1A (c.3521C>G, p.T1174S). Previous reports suggest this mutation causes familial hemiplegic migraine and interestingly both the patient's mother, who also carries the mutation, and the patient's maternal grandmother, have frequent migraines with aura.