Hereditary Leucodystrophy in the Mouse: The New Mutant Twitcher

A new inherited neurological disease in the mouse (the mutant twitcher) has been studied. Transmission is by an autosomal recessive gene (twi). Affected animals are apparently normal at birth but develop a generalized tremor at about 3 weeks of age followed by progressive weakness and wasting. The disease is fatal by 3 months. The principal pathological changes affect the myelin of both central and peripheral nervous systems. Degeneration of myelin sheaths and the presence of multinucleated macrophages with PAS-positive cytoplasm are characteristic findings. Peripheral nerves show remyelination following demyelination. Electron microscopically the macrophages contain a variety of inclusions in which there are crystalline and multi-angular structures and twisted tubules. The abnormalities closely resemble those found in globoid cell leucodystrophy (Krabbe's disease) in man.