Clinical variation in 2 related children with neuronopathic Gaucher disease

The clinical features in 2 second cousins with neuronopathic Gaucher disease include slowly progressive ataxia, spasticity, myoclonus, and seizures with relative preservation of intellectual function. Organomegaly was noted only in Patient 1. Both patients had diffuse slowing with paroxysmal features in electroencephalograms and a deficiency of beta-glucosidase activity in leukocytes and skin fibroblast cultures. The parents of Patient 1 and the related father of Patient 2 had levels of beta-glucosidase activity consistent with the carrier state for Gaucher disease. The value of beta-glucosidase activity in the mother of Patient 2 suggests a different mutation, the result being a defective enzyme component not detectable by measuring total activity.