Mucopolysaccharidosis Type VII

Mucopolysaccharidosis type VII: Understanding and clinical features

Introduction:

Mucopolysaccharidosis type VII (MPS VII), also known as Sledden syndrome, is a rare genetic disorder that results in impaired mucopolysaccharide metabolism. This inherited disease is caused by a defect in the enzyme beta-glucuronidase, which leads to the accumulation of glycosaminoglycans (GAGs) in various tissues of the body. MPS VII has similar clinical manifestations to MPS type I, but differs from it in the absence of corneal opacification. In this article, we will review the main aspects of MPS VII, including its causes, clinical presentation, and treatment approaches.

Causes and inheritance:

MPS VII is caused by a genetic defect caused by a mutation in the GUSB gene, which is responsible for encoding beta-glucuronidase. This enzyme plays an important role in the breakdown of GAGs such as hyaluronan, dermatan sulfate and heparan sulfate. As a result of a defect in beta-glucuronidase, these mucopolysaccharides accumulate in various tissues of the body.

The mode of inheritance of MPS VII is unknown. However, like other forms of mucopolysaccharidosis, MPS VII is assumed to be inherited in an autosomal recessive manner, meaning that both parents must be carriers of the affected gene for a child to show signs of the disease.

Clinical manifestations:

Patients with MPS VII have a variety of clinical symptoms that can vary in severity. Common features of MPS VII are psychomotor retardation, skeletal abnormalities, organomegaly (enlargement of internal organs), and visual impairment.

Delayed psychomotor development can manifest itself in the form of mental retardation and delayed physical development. Skeletal abnormalities include gross bone deformities, bone defects, and limited joint mobility. Organomegaly can lead to an enlarged liver and spleen, as well as other changes in the internal organs.

A special feature of MPS VII is the absence of corneal opacity, which is characteristic of MPS type I. This is a distinguishing feature that can help differentiate between these two types of mucopolysaccharidosis.

Treatment:

To date, there is no specific therapy that can completely cure MPS VII. However, some approaches have been developed to treat symptoms and slow the progression of the disease.

One treatment method is enzyme replacement therapy (ERT). In the case of MPS VII, ERT aims to administer artificially created beta-glucuronidase to compensate for its deficiency in the body. This may help reduce GAG ​​accumulation and improve some symptoms of the disease. However, ERT is unable to cross the blood-brain barrier, limiting its effectiveness against central nervous system manifestations of MPS VII.

Another approach is bone marrow transplantation, which may be considered in some cases of MPS VII. A bone marrow transplant can provide healthy cells capable of producing the missing enzyme to the patient's body. However, this procedure carries serious risks and requires careful discussion with medical professionals.

Symptom control and supportive care also play an important role in the management of MPS VII. This may include physical therapy, occupational therapy, specialized treatment for bone and joint conditions, and measures to support organ function.

Conclusion:

MPS VII is a rare inherited disease caused by a defect in the GUSB gene and the accumulation of GAGs in various tissues of the body. It presents with a wide range of symptoms, including psychomotor retardation, skeletal abnormalities, and organomegaly. Treatment of MPS VII is limited to supportive measures and some specific approaches such as enzyme replacement therapy and bone marrow transplantation. Further research and development of new therapeutic approaches may play an important role in improving the prognosis and quality of life of patients suffering from MPS VII.