The acne genes

Acne is one of the most common skin diseases. Many epidemiologic studies and twin studies have provided substantial evidence about the genetic influence in the development of acne [1-5], at least in certain stages of acne such as neonatal acne, teenage acne [6], adult persistent acne, or in special forms of acne such as acne comedonica, acne inversa [7, 8], acne fulminans [9], or in acne severity [10] and therapeutic resistance [11]. Acne is very likely mediated by polygenic inheritance or multifactorial inheritance attributed to the interplay between multiple genes and the environment, especially the sex hormones. It is unknown if each candidate acne gene contributes equally or additively to the disease phenotype, or whether there exists a master gene that presides or leads the disease development. All the candidate genes may influence each other and perpetuate the disease process. The problem in many of the existing epidemiologic studies may include (1) a small sample size with single or few families examined without matched control; (2) lack of standardization in the disease definition or severity classification; (3) variability of age onset, duration, course, and psychosocial influence.