Phobic anxiety disorder in hereditary hyperekplexia – Comorbidity or a coincidence: Case reports of two siblings

Hyperekplexia (startle disease) is a rare non-epileptic neurological entity resulting from gene mutation. The onset of this disorder is usually in infancy, but can be delayed until early adulthood. Patients with this disorder usually have normal mental development. Patients with hyperekplexia may present with symptoms ranging from sub-syndromal anxiety, to symptoms of syndromal anxiety disorder. This case report is about two siblings with hyperekplexia, in whom phobic anxiety disorder was a prominent manifestation.