Melanocytic involvement in giant axonal neuropathy.

The skin of a patient with giant axonal neuropathy was studied by light and electron microscopy. Enlarged melanocytes protruded into the papillary dermis. An increased number of microfilaments (100 A), which accumulated in rounded or irregular clusters was the main pathological feature. Melanosomes and melanisation were normal. A similar increase of microfilaments was seen in axons and Schwann cells of peripheral nerves, fibroblasts and endothelial cells. This suggests that this metabolic, probably inborn and genetic disorder, does not only affect the nervous system but also the whole microfilament system (cytoskeleton).