Introduction
Niemann-Pick's disease(Niemaoh-Pick disease referred to as NPD) Also known as sphingomyelin lipidosis (sphingomyelin lipidosis), familial lipid-like metabolic disorders. It is characterized by a large number of foam cells containing sphingomyelin in whole mononuclear macrophages and the nervous system. Higher Xue's disease is rare. It is autosomal recessive, with more Jewish morbidity, with an incidence of up to 1/25,000. There are currently at least five types.
Cause
Nimann reported 1 case in 1914, and the patient died at 18 months of age. It was discovered in 1934 that it is a neurophosphorus sedimentary disease. It was only discovered in 1966 that it was caused by a lack of neurophospholipidase (sphingomyelinase). After the enzyme is absent, the systemic sphingomyelin metabolism is disordered, and the neurolipids are deposited in the mononuclear-macrophage system and nerve tissue cells.
This disease is a sphingomyelinase deficiency caused by sphingomyelin metabolism disorders. The latter accumulates in the mononuclear-macrophage system, with hepatic and splenomegaly, and degeneration of the central nervous system.
The sphingomyelin is formed by the attachment of N-sphingosine to a molecule of phosphocholine at the C1 site. The sphingomyelin is derived from various cell membranes, red blood cell matrices and the like. After phagocytosis by macrophages during cellular metabolic senescence.
The activity of this enzyme is highest in normal liver, and the liver, kidney and brain small intestine are also rich in this enzyme. The activity of the enzyme in the liver, spleen and other tissues of the patient is reduced to less than 50%.
symptom
More common in infants and young children under 2 years old, also in the neonatal period. The main symptoms are hepatosplenomegaly, anemia, and a longer course of disease, malnutrition, developmental delay. Some may have deafness, convulsions, muscle rigidity and hypotonia, and Niemann-Pick cells can be diagnosed in the bone marrow. The five types are as follows:
1, acute neurotype (type A or infant type) is a typical Niemann-Pick (85%), mostly within 3 to 6 months after birth, a few cases after a few weeks after birth or after 1 year of age. Initially loss of appetite, vomiting, feeding difficulties, extreme weight loss, dry skin is waxy yellow, progressive intelligence, exercise loss, low muscle tone, eventually become an idiot, half of the cherry erythema (cherryred spot), blindness, jaundice Liver and spleen. Anemia, dyscrasia, mostly due to infection before the age of 4 died. The skin often has a small yellow tumor-like rash with deafness. The accumulation of sphingomyelin is 20 to 60 times normal, and the enzyme activity is 5 to 10% of normal and the lowest is <1%.
2, non-neurotype (β-type or visceral type) Infants or children, the beginning of the disease, the progress of the disease is slow, the hepatosplenomegaly is prominent. Normal intelligence, no neurological symptoms. Can live to adults. The cumulative amount of SM is 3 to 20 times normal, the enzyme activity is 5 to 20% of normal, and the lower one is the same as type A.
3, juvenile type (C type chronic neurological type) more common children, a small number of children or adolescents. After birth, the development is more normal, and a few have early jaundice. Often the first hepatosplenomegaly, most of the symptoms of neurological symptoms in 5 to 7 years old (may be earlier or late in adolescence). Mental decline, language barriers, learning difficulties, emotional variability, gait instability, ataxia, tremors, muscle tension and hyperreflexia, convulsions, dementia, cherry erythema or supranuclear vertical eye muscles. Can live to 5 to 20 years old, and individual can live to 30 years old. The cumulative amount of SM is 8 times normal, and the enzyme activity is up to 50% of normal, which is also close to normal or normal.
4, Nova-scotia type (D type) Clinically, the younger type is slower, with obvious jaundice, hepatosplenomegaly and neurological symptoms, more deaths than school age, and reduced enzyme activity.
5, adult adult onset, normal intelligence, no neurological symptoms, varying degrees of hepatosplenomegaly. Can survive for a long time. The cumulative amount of SM was 4 to 6 times normal, and the enzyme activity was normal.
diagnosis
1 hepatosplenomegaly;
2 with or without neurological damage or erythema of the fundus;
3 external peripheral blood lymphocytes and monocyte cytoplasm have vacuoles;
4 bone marrow can find foam cells;
5X line lung is miliary or reticular infiltration;
6 conditions can be used for the determination of sphingomyelinase activity, sphingomyelin excretion, liver, spleen or lymph node biopsy confirmed.
Identification
1, high snow disease infant type: mainly liver, when the muscle tension is paralyzed, sputum, no fundus cherry erythema, lymphocyte slurry without vacuole, serum acid phosphatase increased, high snow cells found in the bone marrow.
2, Wolman disease: no fundus cherry erythema, X-ray abdominal plain film can be seen double adrenal gland enlargement, the shape is unchanged, there is diffuse punctate calcification shadow. There are vacuoles in the cytoplasm of lymphocytes.
3, GM gangliosidase lipid disease type I: birth has a appearance characteristics, high forehead, low nose, thick skin, 50% of cases have fundus cherry erythema and lymphocyte pulp vacuoles. X-rays can be seen in multiple bone dysplasia, especially vertebrae.
4, Hurler disease (mucopolysaccharide type I): liver spleen, poor intelligence, lymphocytes in the cytoplasm of the lymphocytes, bone marrow with foam cells and other similar to NPD. Heart defect, multiple bone dysplasia, no lung infiltration. Urinary mucopolysaccharide excretion increases, and neutrophils have special particles. After June, the shape, bone changes, vision loss, corneal opacity.
complication
Can be complicated by rash, deafness, malnutrition, mental decline, ataxia, convulsions, dementia and other neurological symptoms.
treatment
Western medicine treatment
No specific treatment, mainly symptomatic treatment, with a fat diet, strengthen nutrition.
1. Antioxidant Vitamin C, E or butylated hydroxystilbene can prevent the peroxidation and aggregation of unsaturated fatty acids contained in sphingomyelin M and reduce the formation of lipofuscin and free radicals.
2. Splenectomy is suitable for non-neurological type and hypersplenism.
3, embryonic stem transplantation has been successfully reported.
The above content is for reference only, please consult the relevant physician or relevant medical institution if necessary.
prevention
The disease is often recessively inherited by the chromosomes. Most patients are married to close relatives of their parents. According to this situation, the incidence of the disease can be reduced from the perspective of strengthening the strict implementation of the marriage law prohibiting marriage of close relatives, effectively improving the people's physical fitness.
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