OBJECTIVE

To show that the cerebellar ataxias described by Norman and by Jaeken (CDG1a) are the same disease.

METHODS

Seven patients, five females and two males (there were two siblings pairs), who presented a severe cerebellar disease slowly progressive associated with generalized cerebellar atrophy. The sister of one of the patients of the series had been studied because of psychomotor retardation but she died at two years of age due to respiratory problems. An autopsy was carried out that showed severe cerebellar atrophy, and the histological study revealed loss of granular cells and diverse abnormalities of Purkinje's cells, especially focal swellings of 'asteroid bodies' or 'cactus like' type. This suggested to us that Norman's ataxia and CDG1a could be the same pathological entity.

RESULTS

All seven patients had severe cerebellar hypoplasia-atrophy and a small brainstem. Most patients showed peripheral neuropathy with decreased motor nerve conduction velocity, but very little decreased sensory nerve conduction velocity. All seven patients had highly raised serum concentrations of asialotransferrin, and heterozygous molecular PMM2 deficit (CDG1a). One of these seven cases was the patient whose sister had histological cerebellar changes corresponding to Norman's ataxia.

CONCLUSIONS

The findings observed in our series suggest that the diseases described by Norman and Jaeken are the same pathological entity and CDG1a can be the biological basis of the histological changes of the cerebellum in Norman's ataxia. We suggest the name of Norman-Jaeken ataxia or disease for this entity.