Albinism is a genetic disease, in which the skin and its accessories lack pigment. It can be divided into systemic albinism and local albinism. The former is the most common. The patient's skin is white, and the hair is silvery white or yellowish; The iris is reddish or light gray, translucent, the pupil is reddish, the retina is colorless, shy, nystagmus, and vision loss; The patient is very sensitive to sunlight. After sun exposure, the skin may thicken and squamous cell carcinoma may occur. The onset of albinism is due to the disorder of melanin metabolism. Melanin in normal human body is synthesized by melanocytes. There are melanosome in melanocytes and tyrosinase in melanosome, which can convert tyrosine into melanin. The number of melanocytes in albino patients is normal, and there are melanosome in the cells. However, due to the mutation of the gene controlling tyrosinase, tyrosinase cannot be synthesized, so tyrosinase in melanosome is missing, and tyrosine cannot be converted into melanin, which leads to whitening of skin, mucosa, hair and eyes. Albinism can be inherited in many ways. Systemic albinism belongs to autosomal recessive inheritance. Local albinism is autosomal dominant inheritance, and ocular albinism (normal skin and hair) can be X recessive or autosomal recessive inheritance. Albinism is all over the world, and the total incidence rate is110000 ~1/20000. At present, there is no effective treatment for albinism, and prevention is the mainstay. Prohibition of consanguineous marriage is one of the important preventive measures. It can also be used for prenatal diagnosis. When pregnant for 4 ~ 5 months, take a small piece of fetal skin through fetal mirror and check whether the fetus is albino under electron microscope to avoid the birth of the child and achieve the goal of prenatal and postnatal care. In terms of genetic mode, albinism belongs to autosomal recessive inheritance. Only when individuals are recessive homozygotes (aa) will they show albinism. Usually, parents of albinos are heterozygotes with normal phenotype, and the genotype is (Aa) disease-causing gene carriers, and there is also a risk of 1/4 in patients.

There is another explanation.

Albinism is a common disease caused by melanin deficiency in skin and its affiliated organs. This kind of patients usually lack melanin in the skin, hair and eyes of the whole body, so there are five kinds of pigments in the retina of the eyes, the iris and pupil are pale pink, they are afraid of light and always squint at things. Skin, eyebrows, hair and other body hairs are all white or white with yellow. People usually refer to such patients as "white-headed sheep".

In fact, the human body presents different skin colors because the melanin contained in human skin is different. Black skin has the most melanin, yellow skin has less melanin, and white skin has the least melanin, so the skin color is very different. Patients with albinism are short of an enzyme-tyrosinase, and the melanocytes in the patient's body can't finally convert tyrosinase into melanin. The gene controlling tyrosinase is located on chromosome 1 1. Therefore, albinism belongs to autosomal recessive inheritance in genetic mode. Only when individuals are recessive homozygotes (aa) will they show albinism. Usually, parents of albinos are heterozygotes with normal phenotype, and the genotype is (Aa) disease-causing gene carriers, and there is also a risk of 1/4 in patients. The incidence of albinism in the population is about1/20000 ~110000.

Basic pathological changes:

The number of epidermal melanocytes is normal and dopa reaction is positive, but there are no or only a few melanocytes.

Clinical features:

A. congenital hereditary pigmentation of skin, hair and eyes.

B due to pigment deficiency, capillaries are exposed, which makes the skin pink.

C. the hair is slender and white or yellow.

D. highly sensitive to ultraviolet rays, prone to solar dermatitis, actinic cheilitis and skin tumors.

E. photophobia,

Clinical differential diagnosis

White fever

Leukocyte abnormal albinism syndrome

Another name

Leukemia; leukemia

Congenital pigment deficiency (congenital colorless)

How to distinguish albinism from vitiligo?

Albinism and vitiligo belong to pigmented skin diseases. Both of them have white spots on the skin as the main clinical manifestation, and there is no obvious itching pain. But albinism and vitiligo are two completely different diseases. Clinically, it can be distinguished from the following aspects:

(1) onset age albinism showed obvious "whitening" from birth; Vitiligo is acquired and can occur at any age, but the number of patients before the age of 20 is the largest.

(2) Family history Albinism has a typical family genetic history; The incidence of vitiligo is related to heredity to some extent, but there is no large amount of statistical data to prove it. China scholars reported that only 3.9% ~ 10.7% of vitiligo was related to heredity.

(3) The generalized albinism in the prone area is the whitening of skin, hair and eyes; Vitiligo can occur anywhere, but it usually occurs in exposed and wrinkled areas.

(4) leukoplakia is characterized by whitening skin, white or yellowish hair, lack of pigment in eyes, photophobia and unclear vision during the day; Vitiligo leukoplakia is localized, with clear edges and slightly darker surrounding pigments. Some white spots are scattered in the island pigment area, with different sizes and shapes. Physical stimulation can induce new leukoplakia or enlarge the original leukoplakia. The hair on the white spot can be white or not.

(5) Pathological examination took the patient's skin tissue and made it into sections, and observed it under the microscope: the melanin in the epidermis of albino patients completely disappeared; However, the melanin in vitiligo patients' leukoplakia decreased or disappeared completely, while the melanin in the margin increased relatively.

(6) The drug treatment for albinism is ineffective, and physical shading can only be used to alleviate the discomfort of patients; Vitiligo will weaken or even disappear after treatment with photosensitive drugs, hormones and traditional Chinese medicine.

What should albinos pay attention to?

Albinism is a hereditary skin disease, and there is no exact and effective treatment at present. Patients with albinism should pay attention to the following aspects: ① Avoid strong sunlight; ② Pay attention to protecting eyes; ③ Avoid consanguineous marriage.

Prenatal and genetic diagnosis of albinism

At present, there is no effective treatment for albinism, so prevention is the main thing, albinism will lead to cancer and mental retardation. Because the disease affects the ability to work and brings pain to patients and their families. Only prenatal diagnosis can prevent a child from being born. Marriage without blood relationship is also an important preventive measure. Prenatal diagnosis and gene diagnosis are the most reliable methods in differential diagnosis at present. Since 1986, some hospitals have directly observed the hair of the fetus in the amniotic cavity with a fetal mirror to diagnose whether the fetus has albinism. The steps are as follows:

Olympus endoscope for disinfection, diameter 2.2 mm, length 16 cm. After disinfection of pregnant women's abdominal skin, dolantin 50 mg was slowly injected intravenously. Under the positioning of B-ultrasound, the puncture point avoids the placenta and is close to the fetal head. A small incision was made in the abdominal skin, the trocar entered the amniotic cavity through the abdominal wall, and the amniotic fluid overflowed. Direct observation of fetal hair under the guidance of B-ultrasound. If it is black, it can be diagnosed as albinism; If it is white, it is diagnosed as albinism; If in doubt, take fetal scalp biopsy and send it for pathological examination. Take out the fetal mirror, stay in hospital for 2 ~ 3 days, protect the fetus if there is uterine contraction, and follow up the birth of the fetus after discharge. According to the characteristics of racial black hair in China, the application of fetal mirror technology can directly diagnose whether the fetus has albinism, thus solving this problem. Although the operation requirements of fetal mirror are high, it usually takes 10 minutes to make a diagnosis under skilled operation.

After years of research, the Institute of Genetics and Development of China Academy of Sciences has found many albino genes and established a series of diagnostic methods for common albino genes. The hospital and xuanwu hospital Dermatology Department jointly established the first albino diagnosis and treatment specialty in China, providing clinical diagnosis, gene consultation and necessary treatment for albino patients and susceptible people. Its fundamental purpose is to intervene on the basis of gene diagnosis and block the inheritance of diseases in the family. Patients only need to draw 5 ml of venous blood, and within one week, they can know the probability of their offspring getting sick, and those who have already got sick can get accurate differential diagnosis reports.

[Edit this paragraph] Daily precautions for patients with albinism

1. Avoid strong sunlight. You can wear a sun hat and long-sleeved clothes to reduce outdoor activities under strong light, thus reducing the possibility of solar dermatitis and even skin cancer.

2. Pay attention to protect your eyes. You can wear sunglasses, avoid using your eyes for a long time, and check your eyesight regularly. We should go to a regular hospital for ophthalmology consultation, adopt scientific and correct methods to correct strabismus and other problems, improve our vision as much as possible or prevent our vision from falling too fast.

3. Improve psychological quality. Although the vast majority of albinos have special appearance and low vision, their intelligence is normal and they need social understanding and help. At the same time, they should cultivate their cheerful and optimistic personality.