Patterns on the skin. New aspects of their embryologic and genetic causes

摘要: The concept of cutaneous mosaicism has now been proven by numerous studies. In this way, the idea that all nevi represent mosaics so far confirmed. We can distinguish five different patterns in human skin form lines Blaschko, checkerboard pattern, phylloid patchy pattern without midline separation, and lateralization. Two etiological categories are epigenetic genomic mosaicism. According to present knowledge caused activity retrotransposons. addition well-known examples functional X-chrosomosome mosaicism, autosomal as observed mice dogs, recently established. Most likely, mechanism may also explain exceptional familial occurrence pigmentary man. Phylloid hypomelanosis speckled lentiginous nevus syndrome described phenotypes be added list lethal mutations surviving type 2 segmental manifestation dominant diseases confrirmed at molecular level a case Hailey-Hailey disease. didymosis why two occur spatial temporal proximity, e.g., cutis tricolor or phacomatosis pigmentovascularis. paradominant inheritance some usually sporadically affect, way exception, several members family. Examples sebaceous Becker nevus. recessive disorders, an event loss homozygosity early developmental stage, giving rise healthy areas arranged nevoid distribution. For example, when dermatologists examine patient with xeroderma pigmentosum they should pay particular attention such revertant