Introduction
Mucopolysaccharide storage type VI is also called Maroteaux-Lamy syndrome, multiple dystrophic dwarfism. It is also an autosomal recessive hereditary disease. The disease is more severe in the 2 to 3 years old, and the incidence of mild cases is older.
Heavy weight is more common in 2 to 3 years old, often with limited joint movement, hernia, limbs contracture, bulky, short neck, short stature. Due to the slow development of the trunk and limbs, the proportion of the body can be imbalanced. In most cases, there are varying degrees of peripheral corneal opacity and loss of hearing. Bell-shaped chest, funnel chest, umbilical hernia and inguinal hernia can also occur. Light cases have a higher age of onset, less skeletal deformities, and slower disease development.
Cause
The disease is autosomal recessive.
symptom
According to the severity of clinical symptoms, this type of mucopolysaccharidosis can be divided into heavy (MPSVI-A) and light (MPSVI-B). Heavy weight is more common in 2 to 3 years old, often with limited joint movement, hernia, limbs contracture, bulky, short neck, short stature. Due to the slow development of the trunk and limbs, the proportion of the body can be imbalanced. The appearance is not as thick as the mucopolysaccharid storage disease type I and type II. The head is slightly larger and the distance between the eyes is too wide. Some cases can also be combined with hydrocephalus. In most cases, there are varying degrees of peripheral corneal opacity and loss of hearing. Bell-shaped chest, funnel chest, umbilical hernia and inguinal hernia can also occur. In the aortic valve area, murmurs caused by aortic regurgitation are often heard. Generally, the liver and spleen are mild to moderately enlarged. It can cause systemic bone changes such as the spine, pelvis, hand and skull. The second cervical dysplasia can lead to atlantoaxial dislocation and thickening of the meninges. It can also cause myelopathy or neurological complications, thoracolumbar vertebral body deformation, and pelvic dysplasia. . This type of patient, like other types of mucopolysaccharidosis, can also have carpal bone dysplasia, deformation and metacarpal bone changes. Herringbone fusion and odontogenic dysplasia can cause neurological complications such as hydrocephalus and spastic paraplegia. Carpal tunnel syndrome often occurs because collagen tissue compresses nerves. Respiratory infections can occur repeatedly. Some can have heart failure. Light cases have a higher age of onset, less skeletal deformities, and slower disease development.
diagnosis
Diagnosis: This type of diagnosis is based on the appearance of typical clinical symptoms. Excessive excretion of dermatan sulfate and leukocytes in the urine produces distinct metachromatic particles (Reilly bodies), and white blood cells or skin or fibroblast cultures show N-acetylgalactose. Amine-4-sulfatase deficiency.
Laboratory tests: Excessive dermatan sulfate in the urine. There are many distinct and heterogeneous particles in neutrophils and lymphocytes.
Other auxiliary examinations: X-ray examination: the same type of mucopolysaccharidosis. Changes in limbs, spine, and pelvis are common. In addition, there are head changes and are characteristic.
(1) Limbs: The tubular bones of the femur and tibia have abnormal bones. In many cases, there are osteophytes and sacral deformities. The long tubular bone of the upper limb changed significantly compared to the lower limb. The short bone changes of the hands and feet vary from person to person, but all have deformities, showing that the metacarpal bone is rod-shaped, and the carpal bone is underdeveloped or deformed.
(2) Spinal column: The change of the thoracolumbar vertebrae is obvious, and the vertebrae are small, showing a bird's beak or other deformities. There may also be kyphosis. The ribs are in the shape of a boat with a sternum protruding forward to make the chest funnel-shaped. The deformation of the ribs can make the chest look like a bell.
(3) Pelvis: The iliac crest is underdeveloped, deformed, the acetabulum is small, and the femoral condyle is irregular and flattened.
(4) Skull: The saddle enlargement is "B" shape, with sclerosing mastoid, odontoid hypoplasia and herringbone seam fusion.
complication
The severity of this disease can be complicated by hydrocephalus and spastic paraplegia, and some can occur heart failure, umbilical hernia and inguinal hernia, liver and spleen mild to moderate swelling.
treatment
Same mucopolysaccharidosis type I. For joint contracture, thoracic deformity, feasible orthopedic treatment, effective infection prevention must also be effective. As for other symptoms such as heart failure, symptomatic treatment can be performed.
prevention
Prevention: Glycogen accumulation disease is a group of children with disorders of hereditary glycogen metabolism. It is characterized by excessive accumulation of glycogen in the body tissue and difficulty in decomposition. It is rarely a metabolic disorder of glycogen, resulting in less glycogen storage in the body. . The glycogen accumulation disease is not a disease but a group of diseases. There are currently 12 identified. Clinically, it is characterized by hypoglycemia, and the organs involved are mainly liver, kidney and skeletal muscle. Most of the genetic methods are autosomal recessive, no gender differences, mostly in childhood. After some patients reach adulthood, the condition is no longer developed and the general health level can be maintained. The patients are mainly due to the lack of certain enzymes that break down glycogen, such as glucose-6-phosphatase, α-1,4 glucose chymase, phosphofructokinase, hepatic phosphorylation kinase, and the like.
Parents of many patients marry close relatives, and avoiding close relatives is an important part of preventing this disease. Once the glycogen accumulation syndrome is found, it is mainly to prevent and treat hypoglycemia, and a small amount of meals, limit fat and total calories, and limit physical activity. Those with high serum lactic acid should take sodium bicarbonate to prevent acidosis. Corticosteroids, adrenaline, glucagon, etc. can help control hypoglycemia.
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