[Diagnosis of Krabbe's leukodystrophy by transmission electron microscopy. Case report].

Krabbe's leukodystrophy is a rare hereditary disease in Mexico. For that reason we report the case of an 11-year-old child. Ultrastructural studies of sural nerve biopsy specimen are described. Myelin sheaths were uniformly thin for the fiber diameters. Cytoplasm of Schwann cells exhibited a moderate dilatation with non-membrane masses with partly curvilinear, needle-shaped structures of variable length. The inclusions often had electron-dense or electron-lucent halos. These inclusions ultrastructurally represented Krabbe's leukodystrophy, and this method aids in the diagnosis in cases that are not available for genetic studies or special laboratory techniques. In this patient, diagnosis of Krabbe's disease was delayed and established several years after the initial symptoms. Electron microscopic examination of a sural nerve provided evidence for a diagnosis of Krabbe's leukodystrophy.