A group of disorders characterized by ectodermal-based malformations and neoplastic growths in the skin, nervous system, and other organs.

Disorders of increased melanin pigmentation that develop without preceding inflammatory disease.

Found in large amounts in the plasma and urine of patients with malignant melanoma. It is therefore used in the diagnosis of melanoma and for the detection of postoperative metastases. Cysteinyldopa is believed to be formed by the rapid enzymatic hydrolysis of 5-S-glutathionedopa found in melanin-producing cells.

A nevus containing melanin. The term is usually restricted to nevocytic nevi (round or oval collections of melanin-containing nevus cells occurring at the dermoepidermal junction of the skin or in the dermis proper) or moles, but may be applied to other pigmented nevi.

A benign, rapidly growing, deeply pigmented tumor of the jaw and occasionally of other sites, consisting of an infiltrating mass of cells arranged in an alveolar pattern, and occurring almost exclusively in infants. Its source of origin is in dispute, the various theories giving rise to its several names. (Dorland, 27th ed)

An autosomal recessive neurocutaneous disorder characterized by severe ichthyosis MENTAL RETARDATION; SPASTIC PARAPLEGIA; and congenital ICHTHYOSIS. It is caused by mutation of gene encoding microsomal fatty ALDEHYDE DEHYDROGENASE leading to defect in fatty alcohol metabolism.

A non-inherited congenital condition with vascular and neurological abnormalities. It is characterized by facial vascular nevi (PORT-WINE STAIN), and capillary angiomatosis of intracranial membranes (MENINGES; CHOROID). Neurological features include EPILEPSY; cognitive deficits; GLAUCOMA; and visual defects.

Facial neoplasms are abnormal growths or tumors that develop in the facial region, which can be benign or malignant, originating from various cell types including epithelial, glandular, connective tissue, and neural crest cells.

An autosomal dominant inherited disorder (with a high frequency of spontaneous mutations) that features developmental changes in the nervous system, muscles, bones, and skin, most notably in tissue derived from the embryonic NEURAL CREST. Multiple hyperpigmented skin lesions and subcutaneous tumors are the hallmark of this disease. Peripheral and central nervous system neoplasms occur frequently, especially OPTIC NERVE GLIOMA and NEUROFIBROSARCOMA. NF1 is caused by mutations which inactivate the NF1 gene (GENES, NEUROFIBROMATOSIS 1) on chromosome 17q. The incidence of learning disabilities is also elevated in this condition. (From Adams et al., Principles of Neurology, 6th ed, pp1014-18) There is overlap of clinical features with NOONAN SYNDROME in a syndrome called neurofibromatosis-Noonan syndrome. Both the PTPN11 and NF1 gene products are involved in the SIGNAL TRANSDUCTION pathway of Ras (RAS PROTEINS).

Autosomal dominant neurocutaneous syndrome classically characterized by MENTAL RETARDATION; EPILEPSY; and skin lesions (e.g., adenoma sebaceum and hypomelanotic macules). There is, however, considerable heterogeneity in the neurologic manifestations. It is also associated with cortical tuber and HAMARTOMAS formation throughout the body, especially the heart, kidneys, and eyes. Mutations in two loci TSC1 and TSC2 that encode hamartin and tuberin, respectively, are associated with the disease.

Tumors or cancer of the CONJUNCTIVA.

Coloration or discoloration of a part by a pigment.

Insoluble polymers of TYROSINE derivatives found in and causing darkness in skin (SKIN PIGMENTATION), hair, and feathers providing protection against SUNBURN induced by SUNLIGHT. CAROTENES contribute yellow and red coloration.

A characteristic symptom complex.