The majority of patients with West syndrome have structural brain abnormalities. A proportion of cases have a genetic etiology and inheritance pattern depends on the gene involved.
Gene abnormalities associated with West syndrome include ARX, CDKL5, SPTAN1, STXBP1. Genetic etiologies are also recognized to underlie structural brain abnormalities, such as TSC1 and TSC2 in tuberous sclerosis.
Family history of seizures or epilepsy is rare. The presence of a family history should lead to investigation for specific genetic or metabolic etiologies.