Scheie syndrome

A rare genetic disorder

Classification
External resources

Scheie syndrome is a rare genetic disorder that is classified as a type of mucopolysaccharidosis, specifically Mucopolysaccharidosis type I (MPS I). It is the mildest form of MPS I, with the other forms being Hurler syndrome and Hurler-Scheie syndrome.

Pathophysiology

Scheie syndrome is caused by a deficiency of the enzyme alpha-L-iduronidase, which is responsible for breaking down glycosaminoglycans (GAGs), specifically dermatan sulfate and heparan sulfate. The accumulation of these substances in the body leads to the various symptoms associated with the disorder.

Genetics

Scheie syndrome is inherited in an autosomal recessive manner. This means that an individual must inherit two copies of the defective gene, one from each parent, to manifest the disease. The gene responsible for Scheie syndrome is located on chromosome 4p16.3.

Clinical Features

Individuals with Scheie syndrome typically present with symptoms later in childhood or adolescence. Common clinical features include:

• Joint stiffness and contractures
• Corneal clouding
• Carpal tunnel syndrome
• Hearing loss
• Cardiac abnormalities, such as valvular heart disease
• Hernias

Unlike the more severe forms of MPS I, individuals with Scheie syndrome usually have normal intelligence and a normal lifespan.

Diagnosis

The diagnosis of Scheie syndrome is based on clinical evaluation, family history, and laboratory tests. Enzyme assays can measure the activity of alpha-L-iduronidase in blood or fibroblasts. Genetic testing can confirm mutations in the IDUA gene.

Treatment

There is no cure for Scheie syndrome, but treatment focuses on managing symptoms and improving quality of life. Options include:

• Enzyme replacement therapy (ERT) with laronidase
• Surgical interventions for carpal tunnel syndrome and corneal clouding
• Physical therapy to maintain joint mobility

Prognosis

The prognosis for individuals with Scheie syndrome is generally good, with most individuals leading a normal lifespan. However, they may experience progressive symptoms that require ongoing management.

Related pages

• Mucopolysaccharidosis
• Hurler syndrome
• Hurler-Scheie syndrome
• Genetic disorders