Pooling and in-depth analysis of cases taken from the literature and from French experience of patients suffering from early-stage neurological forms of Gaucher disease have made it possible to demonstrate the existence of more than two neurological forms which differ in terms of their natural history, clinical picture and response to enzyme therapy. The perinatal, lethal form is characterised by foetal and placental ânasarca, foetal death, prematurity or life-threatening distress at birth. The specific clinical signs include ichtyosis, muscle and tendon retraction and facial dysmorphism. Type 2 Gaucher disease affects infants and leads to death before the age of 2 years. Organ damage is characterised by the severity of pneumopathy. Neurological signs are of particular importance and include hyperextension of the neck and disorders affecting oculomotricity, sucking and swallowing. Most patients also develop episodes of apnoea which become increasingly lengthy and frequent as the disease progresses. Myoclonic epilepsy, which appears to be scarcely susceptible to enzyme therapy, and psychomotor regression are less common and are mainly seen in the rare cases of prolonged survival and in type 3 Gaucher disease.