Troyer Syndrome

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What is Troyer syndrome?

Troyer syndrome (also known as spastic paraplegia gene, SPG20) belongs to a group of nervous system disorders called hereditary spastic paraplegias. The main feature of these disorders are muscle weakness and spasms in the legs that tend to get worse over time.

Troyer syndrome usually begins in early childhood. It results from a mutation in SPGP20 located in chromosome 13. The mutation causes loss of the spartin proteins.

Troyer syndrome is an autosomal recessive disorder, which means that both parents must carry it and pass on the defective gene. The disease was first observed in Amish families in Ohio. Diagnosis is made by specialized genetic testing.

In addition to muscle weakness and muscle spasms in the legs, other symptoms include:

  • Permanent shortening of one or both legs
  • Difficulty walking
  • Speech disorders
  • Drooling
  • Weakening of the hand muscles
  • Developmental delays
  • Fluctuating emotions
  • Short stature

The outlook for people with Troyer syndrome varies. Some people may have a mild form of the disease, while others eventually lose the ability to walk normally. Troyer syndrome does not shorten the normal life span.

There are no specific treatments to prevent or slow the progressive degeneration seen in Troyer syndrome. Symptomatic therapy includes antispasmodic drugs and physical therapy to improve muscle strength and maintain range of motion in the legs. Assistive devices may be needed to help with walking.

Learn About Clinical Trials
Clinical trials are studies that allow us to learn more about disorders and improve care. They can help connect patients with new and upcoming treatment options.

How can I or my loved one help improve care for people with Troyer syndrome?

Consider participating in a clinical trial so clinicians and scientists can learn more about Troyer syndrome and related disorders. Clinical research uses human volunteers to help researchers learn more about a disorder and perhaps find better ways to safely detect, treat, or prevent disease.

All types of volunteers are needed—those who are healthy or may have an illness or disease—of all different ages, sexes, races, and ethnicities to ensure that study results apply to as many people as possible, and that treatments will be safe and effective for everyone who will use them.

For information about participating in clinical research visit NIH Clinical Research Trials and You. Learn about clinical trials currently looking for people with Troyer syndrome at

Where can I find more information about Troyer syndrome?

Genetic Alliance, Inc.
Phone: 202-966-5557 or 800-336-4363

National Organization for Rare Disorders (NORD)
Phone: 203-744-0100 or 800-999-6673; 844-259-7178 Spanish

Spastic Paraplegia Foundation
Phone: 877-773-4483

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