Heritable nail diseases.

Heritable nail diseases are associated with a great variety of inherited diseases and syndromes. Well over 60 HEDs and numerous other inherited nail abnormalities are known to exist. A classification system of these disorders, as well as the specific nail change found in each, has been presented. Table 1 has been included to correlate many of the nail disorders with their corresponding inherited disease or syndrome. Clinically, inherited nail diseases may appear to be of questionable importance. In cases of primary presentation or poor historical background, however, these subtle nail changes may prove useful in arriving at or substantiating a diagnosis.