Hypopigmentation
A condition caused by a deficiency or a loss of melanin pigmentation in the epidermis, also known as hypomelanosis. Hypopigmentation can be localized or generalized, and may result from genetic defects, trauma, inflammation, or infections.
Pigmentation Disorders
Albinism, Ocular
Albinism affecting the eye in which pigment of the hair and skin is normal or only slightly diluted. The classic type is X-linked (Nettleship-Falls), but an autosomal recessive form also exists. Ocular abnormalities may include reduced pigmentation of the iris, nystagmus, photophobia, strabismus, and decreased visual acuity.
Albinism, Oculocutaneous
Heterogeneous group of autosomal recessive disorders comprising at least four recognized types, all having in common varying degrees of hypopigmentation of the skin, hair, and eyes. The two most common are the tyrosinase-positive and tyrosinase-negative types.
Hair Color
Color of hair or fur.
Hermanski-Pudlak Syndrome
Syndrome characterized by the triad of oculocutaneous albinism (ALBINISM, OCULOCUTANEOUS); PLATELET STORAGE POOL DEFICIENCY; and lysosomal accumulation of ceroid lipofuscin.
Melanosomes
Melanin-containing organelles found in melanocytes and melanophores.
Hyperpigmentation
Excessive pigmentation of the skin, usually as a result of increased epidermal or dermal melanin pigmentation, hypermelanosis. Hyperpigmentation can be localized or generalized. The condition may arise from exposure to light, chemicals or other substances, or from a primary metabolic imbalance.
Vitiligo
A disorder consisting of areas of macular depigmentation, commonly on extensor aspects of extremities, on the face or neck, and in skin folds. Age of onset is often in young adulthood and the condition tends to progress gradually with lesions enlarging and extending until a quiescent state is reached.
Adaptor Protein Complex beta Subunits
Monophenol Monooxygenase
Platelet Storage Pool Deficiency
Waardenburg Syndrome
Rare, autosomal dominant disease with variable penetrance and several known clinical types. Characteristics may include depigmentation of the hair and skin, congenital deafness, heterochromia iridis, medial eyebrow hyperplasia, hypertrophy of the nasal root, and especially dystopia canthorum. The underlying cause may be defective development of the neural crest (neurocristopathy). Waardenburg's syndrome may be closely related to piebaldism. Klein-Waardenburg Syndrome refers to a disorder that also includes upper limb abnormalities.
Melanocytes
Mammalian pigment cells that produce MELANINS, pigments found mainly in the EPIDERMIS, but also in the eyes and the hair, by a process called melanogenesis. Coloration can be altered by the number of melanocytes or the amount of pigment produced and stored in the organelles called MELANOSOMES. The large non-mammalian melanin-containing cells are called MELANOPHORES.
Nystagmus, Congenital
Nystagmus present at birth or caused by lesions sustained in utero or at the time of birth. It is usually pendular, and is associated with ALBINISM and conditions characterized by early loss of central vision. Inheritance patterns may be X-linked, autosomal dominant, or recessive. (Adams et al., Principles of Neurology, 6th ed, p275)
Albinism
General term for a number of inherited defects of amino acid metabolism in which there is a deficiency or absence of pigment in the eyes, skin, or hair.
SOXE Transcription Factors
Melanins
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.
Microphthalmia-Associated Transcription Factor
A basic helix-loop-helix leucine zipper transcription factor that regulates the CELL DIFFERENTIATION and development of a variety of cell types including MELANOCYTES; OSTEOCLASTS; and RETINAL PIGMENT EPITHELIUM. Mutations in MITF protein have been associated with OSTEOPETROSIS and WAARDENBURG SYNDROME.
Prader-Willi Syndrome
An autosomal dominant disorder caused by deletion of the proximal long arm of the paternal chromosome 15 (15q11-q13) or by inheritance of both of the pair of chromosomes 15 from the mother (UNIPARENTAL DISOMY) which are imprinted (GENETIC IMPRINTING) and hence silenced. Clinical manifestations include MENTAL RETARDATION; MUSCULAR HYPOTONIA; HYPERPHAGIA; OBESITY; short stature; HYPOGONADISM; STRABISMUS; and HYPERSOMNOLENCE. (Menkes, Textbook of Child Neurology, 5th ed, p229)
Chromosomes, Human, Pair 15
Pigment Epithelium of Eye
Hair
A filament-like structure consisting of a shaft which projects to the surface of the SKIN from a root which is softer than the shaft and lodges in the cavity of a HAIR FOLLICLE. It is found on most surfaces of the body.