Familial non-obese idiopathic intracranial hypertension.

Purpose: To report a series of cases of non-obese familial idiopathic intracranial hypertension. Observation: One father and three offsprings (two brothers and one sister) with idiopathic intracranial hypertension and different phenotypic presentations. Conclusion and Importance: Familial idiopathic intracranial hypertension may underrecognized and may not be associated with obesity. Symptomatic family members may need to be screened for IIH in some cases.