Gingival biopsy in the diagnosis of giant axonal neuropathy

We report the case of a 4-year-old child presenting with a diagnosis of giant axonal neuropathy. This rare condition was diagnosed when the child was 15 months old and was confirmed using a gingival sample removed during a dental examination. Structural and ultrastructural analyses demonstrated the presence of numerous unmyelinated fibres with distended axons and the accumulation of intermediate filaments in Schwann cells, in fibroblasts and in endothelial cells. Cytological examination of connective tissue revealed the presence of mitochondria-like particles. Scanning electron microscopic examination of hair revealed the presence of a longitudinal groove along the shaft. These characteristic features of giant axonal neuropathy demonstrate that gingival tissue can be used as an aid in its diagnosis.