Clinical and inheritance profiles of hyperekplexia in Jordan.

Hyperekplexia is a rare nonepileptic disorder characterized by excessive startle response to acoustic, visual, or other stimuli. Patients with hyperekplexia are often misdiagnosed as having epilepsy. The presentation modalities, phenotypes, and the modes of inheritance among patients with hyperekplexia from 9 Jordanian families are described. All families were referred with the preliminary diagnosis of uncontrolled seizures with onset of the disease in the neonatal period and with variable and atypical presenting features. The inheritance profile in 4 families was compatible with autosomal recessive and in 1 family with autosomal dominant inheritance. Four families showed sporadic cases of hyperekplexia. This is the first report of a series of patients with hyperekplexia from Jordan. The clinical manifestations show atypical features that have not been previously reported, pointing to the probable broader clinical spectrum of this entity. Recognition of the syndrome allows for prompt proper management and provision of genetic counseling.