Partial seizures with focal epileptogenic electroencephalographic patterns in three related female patients with fragile-X syndrome.

Epilepsy and abnormal electroencephalographic (EEG) patterns have been reported in mentally retarded males with fragile-X syndrome, but the high incidence of epilepsy in such persons has been recognized only recently. These individuals have focal spikes in the EEG similar to the benign rolandic pattern. Female carriers have very rarely been reported to have epilepsy or nonspecific abnormal EEG patterns. We report partial seizures with a focal epileptogenic EEG pattern in two sisters and their grandmother, who are all carriers of fragile-X syndrome. The sisters have mild developmental delay, but the grandmother is of normal intelligence. The mother of the two sisters is known to be a carrier of the fragile-X chromosome and is of normal intelligence, with no history of seizures. It is important for physicians to be aware of the possibility that females presenting with partial seizures of unknown cause may be fragile-X carriers, and enquiry for a family history of intellectual disability should be pursued.