Ichthyosis vulgaris and pycnodysostosis: an unusual occurrence.

Pycnodysostosis is a rare autosomal recessive disorder whose gene responsible for this phenotype (CTSK), mapped to human chromosome 1q21, code for the enzyme cathepsin K, a lysosomal cysteine protease; with an estimated incidence of 1.7 per 1 million births. This clinical entity includes micromelic dwarfism, increased radiological bone density, dysplasia of the skull, acro-osteolysis, straightening of the mandibular angle and in some cases, dysplasia of the acromial end of the clavicle. Oral and maxillo-facial manifestations of this disease are very clear. Herein we reported a case of pycnodysostosis, showing short stature with widening of the sutures, unfused anterior and posterior fontanelles, crowding of teeth with dental caries and typical radiological features associated with ichthyosis vulgaris and palmoplantar keratoderma.