Axilla skin biopsy: a reliable test for the diagnosis of Lafora's disease.

Skin biopsies from the axilla were examined in 7 patients with clinical signs and symptoms of Lafora's disease, in 9 relatives (7 parents and 2 siblings), and in 17 patients with chronic or progressive degenerative neurological disorders and chronic epilepsy, who served as controls. In the biopsies of all patients with Lafora's disease, typical periodic acid-Schiff (PAS)-positive inclusions were present in the myoepithelial cells of the secretory acini of the apocrine glands and/or in the cells of the eccrine duct. No abnormalities were found in the biopsies from relatives and controls. We conclude that axilla skin biopsy is an easy and reliable test for diagnosing Lafora's disease, and is preferable to liver biopsy, but has no value for carrier detection.