Clinico-pathological study on macular mutant mouse.

The macular mutant mouse was clinically and pathologically examined. The hemizygotes began to show white fur color and curly whiskers around postnatal day 3, then seizures and ataxia around day 8, while the normal littermates did not. The hemizygotes also increased weight gradually from birth to day 9, but then showed weight loss and died around day 15 with severe emaciation. These clinical features resembled those in Menkes kinky hair disease. There were no pathological changes in the cerebral cortex in the hemizygotes on day 7. On day 10, two to three clear vacuoles began to appear in a few neurons in the cerebrum. These neurons with vacuoles increased gradually in number and degenerative neurons were also observed by day 14. Ultrastructurally, they corresponded to giant abnormal mitochondria with an electron-lucent matrix and short peripherally located cristae. Other abnormal mitochondria, which were characterized by an electron-dense matrix with tubular or vesicular cristae, were also observed in the cerebral cortical neurons.