We report three brothers belonging to a consanguineous family and suffering from ataxia telangiectasia with severe early neurogenic amyotrophy. Pathological examination of the brain and spinal cord in one of them showed Purkinje cell loss with empty baskets and numerous axonal spheroids, dorsal column demyelination with astrocytic proliferation and severe anterior horn cell degeneration. We consider these pathological findings to be related to Louis-Bar disease. Anterior horn cell changes may be one of the early pathological features in ataxia telangiectasia.