Caption

Papillon-Lefevre syndrome. Coloured transmission electron micrograph (TEM) of a cell affected by Papillon-Lefevre syndrome, a rare inherited condition. Plaques of the protein keratin (blue) are seen within the cell. The disease causes hyperkeratosis (thickening of the skin) and severe periodontitis, an inflammation of the tissue that surrounds and supports the teeth. The inflammation results in bone and tooth loss. Magnification: x16,600 when printed at 10 centimetres wide.