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Spastic paraplegia type 8
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Reviewed March 2009
What is spastic paraplegia type 8?
Spastic paraplegia type 8 is part of a group of genetic disorders known as hereditary spastic paraplegias. These disorders are characterized by progressive muscle stiffness (spasticity) and the development of paralysis of the lower limbs (paraplegia). Hereditary spastic paraplegias are divided into two types: pure and complex. The pure types involve only the nerves and muscles controlling the lower limbs and bladder, whereas the complex types also have significant involvement of the nervous system in other parts of the body. Spastic paraplegia type 8 is a pure hereditary spastic paraplegia.
Like all hereditary spastic paraplegias, spastic paraplegia type 8 involves spasticity of the leg muscles and muscle weakness. People with this condition can also experience exaggerated reflexes (hyperreflexia), a decreased ability to feel vibrations, muscle wasting (amyotrophy), and reduced bladder control. The signs and symptoms of spastic paraplegia type 8 usually appear in early to mid-adulthood. As the muscle weakness and spasticity get worse, some people may need the aid of a cane, walker, or wheelchair.
How common is spastic paraplegia type 8?
The prevalence of all hereditary spastic paraplegias combined is estimated to be 1 to 18 in 100,000 people worldwide. Spastic paraplegia type 8 likely accounts for only a small percentage of all spastic paraplegia cases.
What genes are related to spastic paraplegia type 8?
Mutations in the KIAA0196 gene cause spastic paraplegia type 8. The KIAA0196 gene provides instructions for making a protein called strumpellin. Strumpellin is active (expressed) throughout the body, although its exact function is unknown. The protein's structure suggests that strumpellin may interact with the structural framework inside cells (the cytoskeleton) and may attach (bind) to other proteins.
KIAA0196 gene mutations are thought to change the structure of the strumpellin protein. It is unknown how the altered strumpellin protein causes the signs and symptoms of spastic paraplegia type 8.
Read more about the KIAA0196 gene.
How do people inherit spastic paraplegia type 8?
Spastic paraplegia type 8 is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder.
In most cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family.
Where can I find information about diagnosis or management of spastic paraplegia type 8?
These resources address the diagnosis or management of spastic paraplegia type 8 and may include treatment providers.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.
Where can I find additional information about spastic paraplegia type 8?
You may find the following resources about spastic paraplegia type 8 helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for spastic paraplegia type 8?
What if I still have specific questions about spastic paraplegia type 8?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding spastic paraplegia type 8?
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (4 links)
The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.