Spastic paraplegia type 31

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What is spastic paraplegia type 31?

Spastic paraplegia type 31 is one 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) caused by degeneration of nerve cells (neurons) that trigger muscle movement. Hereditary spastic paraplegias are divided into two types: pure and complicated. The pure types involve only the lower limbs, while the complicated types also involve the upper limbs and other areas of the body, including the brain. Spastic paraplegia type 31 is usually a pure hereditary spastic paraplegia, although a few complicated cases have been reported.

The first signs and symptoms of spastic paraplegia type 31 usually appear before age 20 or after age 30. An early feature is difficulty walking due to spasticity and weakness, which typically affect both legs equally. People with spastic paraplegia type 31 can also experience progressive muscle wasting (amyotrophy) in the lower limbs, exaggerated reflexes (hyperreflexia), a decreased ability to feel vibrations, reduced bladder control, and high-arched feet (pes cavus). As the condition progresses, some individuals require walking support.

How common is spastic paraplegia type 31?

Spastic paraplegia type 31 is one of a subgroup of hereditary spastic paraplegias known as autosomal dominant hereditary spastic paraplegia, which has an estimated prevalence of one to 12 per 100,000 individuals. Spastic paraplegia type 31 accounts for 3 to 9 percent of all autosomal dominant hereditary spastic paraplegia cases.

What genes are related to spastic paraplegia type 31?

Spastic paraplegia type 31 is caused by mutations in the REEP1 gene. This gene provides instructions for making a protein called receptor expression-enhancing protein 1 (REEP1), which is found in neurons in the brain and spinal cord. The REEP1 protein is located within cell compartments called mitochondria, which are the energy-producing centers in cells, and the endoplasmic reticulum, which helps with protein processing and transport. The REEP1 protein plays a role in regulating the size of the endoplasmic reticulum and determining how many proteins it can process. The function of the REEP1 protein in the mitochondria is unknown.

REEP1 gene mutations that cause spastic paraplegia type 31 result in a short, nonfunctional protein that is usually broken down quickly. As a result, there is a reduction in functional REEP1 protein. It is unclear how REEP1 gene mutations lead to the signs and symptoms of spastic paraplegia type 31. Researchers have shown that mitochondria in cells of affected individuals are less able to produce energy, which may contribute to the death of neurons and lead to the progressive movement problems of spastic paraplegia type 31; however, the exact mechanism that causes this condition is unknown.

How do people inherit spastic paraplegia type 31?

This condition 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 has one parent with the condition.

Where can I find information about diagnosis or management of spastic paraplegia type 31?

These resources address the diagnosis or management of spastic paraplegia type 31 and may include treatment providers.

You might also find information on the diagnosis or management of spastic paraplegia type 31 inEducational resources and Patient support.

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 31?

You may find the following resources about spastic paraplegia type 31 helpful. These materials are written for the general public.

MedlinePlus - Health information (3 links)
Genetic and Rare Diseases Information Center - Information about genetic conditions and rare diseases
Additional NIH Resources - National Institutes of Health
National Institute of Neurological Disorders and Stroke: Hereditary Spastic Paraplegia Information Page
Educational resources - Information pages (6 links)
Patient support - For patients and families (5 links)

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

Gene Reviews - Clinical summary
Genetic Testing Registry - Repository of genetic test information (1 link)
ClinicalTrials.gov - Linking patients to medical research
PubMed - Recent literature
OMIM - Genetic disorder catalog

What other names do people use for spastic paraplegia type 31?

autosomal dominant spastic paraplegia 31
spastic paraplegia 31
SPG31

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines and How are genetic conditions and genes named? in the Handbook.

What if I still have specific questions about spastic paraplegia type 31?

Ask the Genetic and Rare Diseases Information Center

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 31?

autosomal ; autosomal dominant ; cell ; endoplasmic reticulum ; gene ; hereditary ; inherited ;mitochondria ; paraplegia ; pes cavus ; prevalence ; protein ; receptor ; spasticity ; wasting

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

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.