The cluster of Creutzfeldt-Jakob disease among Jews of Libyan origin is the largest in the world. It was found that the disease in this ethnic group is linked to a point mutation in codon 200 of the prion protein precursor gene. In this study the clinical data from 14 such patients are described, demonstrating wide phenotypic heterogeneity. The age of onset ranged from 34 to 65 years and the duration of disease from 2 to 66 months. Clinical features included cerebral, basal ganglia, brainstem, cerebellar, and spinal cord dysfunction. Uncommon features included fatal insomnia in one patient, pruritus in another, and demyelinating peripheral neuropathy in two.