Papillon-Lefèvre syndrome in a 13-year-old boy is described. His two great-grandfathers were first-degree cousins (consanguinity). However, no other case of the syndrome nor of palmoplantar keratoderma exists in the family. The palmoplantar keratoderma, which had started before becoming 1 year of age, is usually more pronounced during spring and autumn as well as during feverish diseases. However, it is of the trans-gradient type and is not necessarily very severe. The loss of the deciduous and permanent teeth was a consequence of severe juvenile parodontitis and of bone destruction. The boy could extract his teeth easily by himself and has total prothesis since the age of 14 years. Every treatment was unsuccessful