Vulvar albinism
Introduction
Introduction to vulvar albinism Vulvaralbinism is a congenital, recessive hereditary disease. It is an autosomal recessive inheritance and is a hereditary disease of congenital pigment deficiency and hair follicle melanin synthesis. It is manifested by the reduction or lack of pigmentation of the whole body skin and hair, or it may only occur locally in the vulva. The patients with this disease involved three kinds of structures for ocular white albinism (OCA), mainly involving the eye whitening disease (OA). Vulvar albinism has no symptoms. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: dermatitis
Cause
Causes of vulvar albinism
(1) Causes of the disease
Ocular white albinism is a heterogeneous autosomal recessive hereditary disease. The close relatives have a significant role in the marriage. The genetic system of albinism is determined by a single recessive gene. Melanocytes cannot form melanin, and may supply free tyrosine. The mechanism is defective, or tyrosinase cannot be transferred to the pre-melanin body.
(two) pathogenesis
Histopathology showed that there were clear cells in the basal layer, negative staining for silver could not prove melanin, dopa staining was positive (tyrosinase positive) or negative (tyrosinase negative).
According to the molecular pathogenesis, OCA can be divided into tyrosinase-related OCA (ie tyrosinase-negative OCA, type I-A; yellow mutant OCA, type I-B; temperature-sensitive OCA, I-TS type; Micro-pigment OCA, type I-MP), tyrosinase-independent OCA (tyrosinase-positive OCA type II), type I patient with tyrosinase gene mutation causing tyrosinase activity deficiency (type IA), activity Decreased (type IB, type I-MP) or enzyme activity is reduced at higher temperatures (type I-TS), tyrosinase is a key enzyme in the melanin biosynthesis pathway, and its lack of activity or reduction can lead to skin pigmentation Reduced or absent, type II patients have P gene deletion or mutation, resulting in the loss of P protein function. P protein is involved in the transport of melanin precursor tyrosine into melanin membrane, which is a protein necessary for melanogenesis. Loss of function can lead to melanin synthesis disorders.
Prevention
Vulvar albinism prevention
To avoid close relatives getting married, OCA protection is more important, usually wear protective glasses.
Complication
Vulvar albinism complications Complications dermatitis
Solar damage, dermatitis is prone to occur after sun exposure.
Symptom
Symptoms of vulvar albinism Common symptoms Tear myopia Astigmatism photophobic nystagmus
There is no symptom of local albinism in the vulva. The genital skin lesion is part of the generalized albinism. It is characterized by pale yellow pubic hair, vulva, labia minora skin milky white or pink, labia minora, vaginal mucosa bright red, and other patients with filamentous light Yellow or silvery white hair, iris light blue, pupil red, often photophobia, tearing, nystagmus and astigmatism, body skin is milky white or pink, soft and dry, due to lack of melanin protection, skin is prone to acute And chronic sun damage, prone to squamous cell carcinoma, basal cell carcinoma.
According to congenital onset and clinical manifestations, there are pure white or pink spots at birth, dermatitis is prone to occur after sun exposure, local boundaries are obvious, histopathology is transparent cells in the basal layer, the number and appearance are normal, and silver staining proves in the epidermis Melanin deficiency; hair whitening or yellowish; iris pink, pupil redness, photophobia.
Examine
Examination of vulvar albinism
Genetic testing, tumor marker examination.
Histopathological examination.
Diagnosis
Diagnosis and differentiation of vulvar albinism
Differential diagnosis
Need to be differentiated from vitiligo, according to the onset of vitiligo, the white spot gradually enlarged from small, no eye symptoms can be identified. It also needs to be differentiated from vulvar sclerotic atrophic disease, which is characterized by loss of vulvar pigmentation, accompanied by symptoms such as tissue atrophy, keratosis and thickening, and itching, cleft palate and ulcers.
