The condition is caused by genetic mutations in one of five genes that encode keratin proteins. Three keratin genes were identified to have a role<unk>  in 1995 with a fourth keratin gene's role in<unk>  identified in 1998. Inheritance<unk>  follows an autosomal dominant pattern of inheritance, which means the defective gene is located on an autosome, and only one copy of the gene is required to inherit the disorder from a parent who has the disorder. On average, 50% of the offspring of an affected person will inherit the disorder, regardless of sex. Occasionally, however, a solitary case can emerge in a family with no prior history of the disorder due to the occurrence of a new mutation (often referred to as a sporadic, spontaneous or de novo mutation).
Pachyonychia congenita
Platonychia
Lipoatrophia annularis
Linitis plastica
Hapalonychia
Steatopygia
Koilonychia
Trachonychia