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Spastic paraplegia type 11
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Reviewed April 2009
What is spastic paraplegia type 11?
Spastic paraplegia type 11 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 the lower limbs. The complex types involve the lower limbs and can affect the upper limbs to a lesser degree. Complex spastic paraplegias also affect the structure or functioning of the brain and the peripheral nervous system, which consists of nerves connecting the brain and spinal cord to muscles and sensory cells that detect sensations such as touch, pain, heat, and sound. Spastic paraplegia type 11 is a complex hereditary spastic paraplegia.
Like all hereditary spastic paraplegias, spastic paraplegia type 11 involves spasticity of the leg muscles and muscle weakness. In almost all individuals with this type of spastic paraplegia, the tissue connecting the left and right halves of the brain (corpus callosum) is abnormally thin. People with this form of spastic paraplegia can also experience numbness, tingling, or pain in the arms and legs (sensory neuropathy); disturbance in the nerves used for muscle movement (motor neuropathy); intellectual disability; exaggerated reflexes (hyperreflexia) of the lower limbs; speech difficulties (dysarthria); reduced bladder control; and muscle wasting (amyotrophy). Less common features include difficulty swallowing (dysphagia), high-arched feet (pes cavus), an abnormal curvature of the spine (scoliosis), and involuntary movements of the eyes (nystagmus). The onset of symptoms varies greatly; however, abnormalities in muscle tone and difficulty walking usually become noticeable in adolescence.
Many features of spastic paraplegia type 11 are progressive. Most people experience a decline in intellectual ability and an increase in muscle weakness and nerve abnormalities over time. As the condition progresses, some people require wheelchair assistance.
How common is spastic paraplegia type 11?
Over 100 cases of spastic paraplegia type 11 have been reported. Although this condition is thought to be rare, its exact prevalence is unknown.
What genes are related to spastic paraplegia type 11?
Mutations in the SPG11 gene cause spastic paraplegia type 11. The SPG11 gene provides instructions for making the protein spatacsin. Spatacsin is active (expressed) throughout the nervous system, although its exact function is unknown. Researchers speculate that spatacsin may be involved in the maintenance of axons, which are specialized extensions of nerve cells (neurons) that transmit impulses throughout the nervous system.
SPG11 gene mutations typically change the structure of the spatacsin protein. The effect that the altered spatacsin protein has on the nervous system is not known. Researchers suggest that mutations in spatacsin may cause the signs and symptoms of spastic paraplegia type 11 by interfering with the protein's proposed role in the maintenance of axons.
Read more about the SPG11 gene.
How do people inherit spastic paraplegia type 11?
This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.
Where can I find information about diagnosis or management of spastic paraplegia type 11?
These resources address the diagnosis or management of spastic paraplegia type 11 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 11?
You may find the following resources about spastic paraplegia type 11 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 11?
What if I still have specific questions about spastic paraplegia type 11?
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 11?
autosomal ; autosomal recessive ; axons ; cell ; corpus callosum ; difficulty swallowing ; dysarthria ; dysphagia ; expressed ; gene ; involuntary ; motor ; muscle tone ; nervous system ; neuropathy ; nystagmus ; paraplegia ; peripheral ; peripheral nervous system ; pes cavus ; prevalence ; protein ; recessive ; scoliosis ; sensory cells ; sensory neuropathy ; spasticity ; tissue ; wasting
You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
See also Understanding Medical Terminology.
References (6 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.