FaCD Online Syndrome Fact Sheet

Last updated: 24 Apr 2013

Name: Piebaldism

Synonym: Piebald trait

Mode of Inheritance: AD

Genes

KIT, mapped to 4q12

Tumor features (possible)

astrocytoma
pituitary adenoma
skin cancer, basal cell

Non-tumor features

axillary freckling
café au lait spots
hypopigmentation of the skin

Comment

Hallmarks of this disorder are congenital white patches of skin and hair, predominantly of forehead, chest, abdomen and limbs[1]. Although apigmented patches are typical, confusingly, café-au-lait spots and freckling can be seen as well, which may lead to the wrong diagnosis of neurfibromatosis type 1 even by experts [2,4]. An increased risk to develop basal cell skin cancer has been reported [1].

Piebaldism in two brothers, one with a pituitary adenoma and another with a grade III astrocytoma has been observed[3].

Piebaldism is caused by germline inactivating mutations of the KIT gene, whereas activating mutations cause familial GIST. Some patients have a cytogenetic deletion of 4q including KIT and present with piebaldism as well as mental retardation and congenital anomalies.

References

[1] Spritz RA. Piebaldism, Waardenburg syndrome, and related disorders of melanocyte development. Semin Cutan Med Surg 16[1], 15-23. 1997.
[2] Spritz RA, Itin PH, Gutmann DH. Piebaldism and neurofibromatosis type 1: horses of very different colors. The Journal of investigative dermatology 2004; 122(2):xxxiv-xxxv.
[3] Gatto M, Giannaula R, Micheli F. [Piebaldism associated with cancer]. Medicina cutánea ibero-latino-americana 1985; 13(6):545-56.
[4] Stevens CA et al. Café-au-lait macules and intertriginous freckling in piebaldism: clinical overlap with neurofibromatosis type 1 and Legius syndrome. American journal of medical genetics. Part A 2012; 158A:1195-9.