Principles of genetics as applied to dermatologic diseases

Skin diseases are frequently genetic in origin; knowing basic genetic principles allows the clinician to understand hundreds of diverse conditions. The structural basis of genetic disease is related to the multiple steps in DNA replication, messenger RNA (m-RNA) production and modification, protein synthesis, and the posttranslational modification of proteins. The multiple steps in these processes are reviewed. Metabolic processes are connected and interconnected by pathways and networks. The general principles of their control are discussed. The modes of inheritance and their distinguishing characteristics are emphasized, as are factors causing variability among those with the same genetic disease. Tables categorizing many genetic diseases are presented, as is a detailed guide to the literature relevant to modern dermatologic genetics.