[Hereditary metabolic diseases with cutaneous manifestations : An update].

Hereditary metabolic diseases are very diverse with variable pathogenetic mechanisms and clinical findings. They can manifest in different organs and, in this respect, dermatologists may play a crucial role in making the right diagnosis if they know to interpret the signs on the skin correctly. Although these are usually rare diseases, the elucidation of the underlying genetic defects has delivered an invaluable contribution to the better pathogenetic understanding of several common diseases over the last years. This is mainly attributable to the fact that the proteins encoded by these genes are often key players within important metabolic signaling pathways of the human organism. We report on new developments in the field of selected porphyria types, hereditary angioedema, pseudoxanthoma elasticum, and hereditary cutaneous leiomyomatosis, all of which constitute a challenge for both dermatologists and other specialists.