Austin type infantile sulfatosis

Introduction to Austin Children's Brain Sulphurosis Austin-type children's brain sulphur-lipid disease, also known as Austin-type metachromatic leukodystrophy, is a joint disease of cerebral sulphur disease and mucopolysaccharidosis. It is characterized by mild Hurler syndrome, multiple bone dysplasia, severe neurological symptoms and markedly low intelligence. basic knowledge The proportion of illness: 0.006% Susceptible people: no specific population Mode of infection: non-infectious Complications: nystagmus, optic atrophy, ataxia

Austin type infant cerebral sulphurosis cause

(1) Causes of the disease

Genetic defects, the lack of galactosyl-3-sulfosaphthyl sulphate sulfatase (CSF) in patients is the main cause of this disease.

(two) pathogenesis

The basic biochemical defect of this disease is the lack of galactosyl-3-sulfosyl sphingosine sulfatase (CSF sulphate), an aryl sulfatase enzyme with three isoenzymes, ie, an aromatic group. Sulfate esterases A, B and C, the gene is located at 22q13. Normally, cerebroside sulphate catalyzes the desulfurization of galactosyl-3-sulfosyl sphingosine, lactosylthioester and galactosyl sphingosine sulfate. Due to the lack of cerebroside sulphate in the patient's body, the above-mentioned several glycosides are incompletely decomposed and may cause disease due to excessive deposition in the brain.

The pathological changes of this disease are most obvious in the central nervous white matter and peripheral nerves, and can also occur in other internal organs. Some neurons in the brain tissue are lost, astrocytes are proliferated, and the cortex has a microglial reaction in the deeper cortex. It remains, white matter shows a significant loss of neurophospholipids, while "U"-shaped nerve fibers are relatively intact, and the number of oligodendrocytes is reduced. Deposited material is found in residual oligodendrocytes and perivascular macrophages, in the dentate nucleus of the cerebellum. In the hypothalamus, thalamus, basal ganglia, pons, spinal anterior horn cells, spinal nerve root ganglion cells and retinal ganglion cells, cytoplasmic inclusion bodies are found, which contain metachromatic substances, under the polarizing microscope, metachromatic The substance is yellow and green. The substance is positive for PAS staining and positive for Sudan black staining. Under electron microscope, the intracellular inclusion bodies are hydrophilic, most of which are located in lysosomes, and the size of inclusion bodies is not Etc. (>1m), mostly composed of concentric or horizontal layered structures in a transparent matrix, each layer being 6-8 nm thick, another inclusion body Consisting of amorphous, thin film such outsourcing inclusion bodies (3 ~ 4nm), produced from the matrix-based, a large extracellular spherical or round particulate matter, under the microscope, these materials have metachromatic.

The pathological changes of optic nerve and peripheral nerve are segmental demyelinating, and there is deposition of metachromatic substances in Schwann cells. Under electron microscope, this substance is polymorphic and composed of "zebra bodies". Dyeing deposits may also be present in renal tubules and bile duct epithelial cells, endocrine gland cells, liver parenchymal cells, and Kupffer cells.

Austin type infant cerebral sulphurosis prevention

Improve the quality of the population, carry out marriage and birth guidance, and strive to reduce the incidence of genetic diseases in the population. Individuals must take effective preventive measures to avoid the birth of genetically ill offspring (ie, the implementation of eugenics) and genetic variation, and take common measures. These include: premarital screening, genetic counseling, prenatal testing and early treatment of genetic diseases.

Austin type infant cerebral sulphuric acid complications Complications, nystagmus, optic atrophy, ataxia

The disease can be complicated by nystagmus, cerebellar lesions, convulsions, optic atrophy, blindness, skeletal malformation caused by multiple bone dysplasia, and occasionally paralytic paraplegia.

Austin-type children with cerebral sulphuric acid symptoms common symptoms gait abnormal irritability, paraplegia, gait, ataxia, slow response

Clinical symptoms begin to appear from 9 months to 2 years old. The earliest manifestations are behavioral abnormalities, irritability, ataxia, uncoordinated movements or abnormal gait. Most cases may have low muscle tone and occasionally paralytic paraplegia. After the lesion lasts for one year, the child can't stand, and the reaction is slower and more obvious. There may be language barriers, increased muscle tone (more obvious lower limbs), weaker or lesser deep reflexes, and ataxia can be further aggravated. Intermittent limb pain, etc., when 3 to 4 years old, the child is bedridden, quadriplegia, nystagmus, cerebellar lesions, convulsions, optic atrophy and slow response are more obvious, fundus examination can find macular With gray discoloration, it can be blinded in the future. In addition to the symptoms of the nervous system, there may be skeletal malformations caused by multiple bone dysplasia, and the face is characterized by mild Hurler syndrome.

Examination of Austin type children's brain sulphurosis

There is an increase in heparan sulfate in the urine, and there is a heterochromatic inclusion body in the peripheral blood. The biochemical analysis of the inclusion body of the brain or liver tissue is an increase in gangliosides, and mainly GM2 and GM3 gangliosides, acetyl sulfate. Heparin is also increasing.

X-ray examination: X-ray showed a similar type of mucopolysaccharidosis, but its degree of change was lighter.

Diagnosis and identification of Austin infants with cerebral sulphur

The disease can be diagnosed based on clinical symptoms, mainly the clinical manifestations of the nervous system, as well as laboratory tests.

In the differential diagnosis, attention should be paid to the identification of several other mucinous storage diseases.

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