Piebaldism

A rare genetic disorder characterized by the absence of melanocytes in certain areas of the skin and hair

Piebaldism

Diagram of skin showing melanocytes

Piebaldism is a rare genetic disorder characterized by the absence of melanocytes in certain areas of the skin and hair, leading to patches of unpigmented skin and hair. This condition is present from birth and is typically inherited in an autosomal dominant pattern.

Genetics

Piebaldism is caused by mutations in the KIT gene, which plays a crucial role in the development and migration of melanocytes during embryonic development. The KIT gene provides instructions for making a protein that is involved in signaling pathways that control cell functions such as growth and division. Mutations in this gene disrupt the normal development of melanocytes, leading to the characteristic patches of depigmented skin and hair.

Clinical Features

Individuals with piebaldism typically have a white forelock of hair, which is a patch of white hair near the front of the scalp. Other areas of the body may also have patches of depigmented skin, most commonly on the forehead, chest, abdomen, and extremities. The borders of these patches are usually well-defined, and the condition does not change significantly over time.

Diagnosis

The diagnosis of piebaldism is primarily clinical, based on the characteristic appearance of the skin and hair. Genetic testing can confirm the diagnosis by identifying mutations in the KIT gene. It is important to differentiate piebaldism from other conditions that cause depigmentation, such as vitiligo or Waardenburg syndrome.

Management

There is no cure for piebaldism, but management focuses on protecting depigmented areas from sunburn and skin cancer. Individuals with piebaldism are advised to use sunscreen and wear protective clothing when exposed to sunlight. Cosmetic options, such as makeup or hair dye, can be used to cover depigmented areas if desired.

Related Conditions

Piebaldism should be distinguished from other conditions that affect pigmentation, such as:

• Vitiligo
• Albinism
• Waardenburg syndrome

Related pages

• Melanocyte
• Genetic disorder
• Autosomal dominant
• KIT gene