A Dutch family with 'familial cortical tremor with epilepsy'. Clinical characteristics and exclusion of linkage to chromosome 8q23.3-q24.1.

Objectives: To describe the clinical characteristics of a large Dutch family with cortical tremor with epilepsy (FCTE) and to test for genetic linkage of FCTE to chromosome 8q23.3-q24.1.

Background: FCTE is an idiopathic generalised epilepsy of adult onset with autosomal dominant inheritance. It is characterised by kinesiogenic tremor and myoclonus of the limbs, generalised seizures, and electrophysiological findings consistent with cortical reflex myoclonus. Genetic analysis has been performed in five Japanese families. In all families, linkage was shown to chromosome 8q23.3-q24.1.

Methods: Clinical and electrophysiological data of a four-generation family, suspected of autosomal dominant inherited FCTE, were collected and linkage analysis was performed. Results Clinical and electrophysiological findings were consistent with a diagnosis of FCTE. Of 41 relatives examined, 13 subjects were considered to be definitely affected, three were probably affected and ten were unaffected. In 15 relatives, the diagnosis could not be established. Linkage to chromosome 8q23.3-q24.1 was excluded.

Conclusions: In this family with autosomal dominant FCTE, specific clinical and electrophysiological features were identified. Exclusion of linkage to chromosome 8q23.3-q24.1 indicates that genetic heterogeneity exists for FCTE.