Congenital generalized hypercontractile muscle stiffness syndrome

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Overview

Congenital generalized hypercontractile muscle stiffness syndrome is a very rare muscle disorder that is present from birth. The name describes the main problem: muscles throughout the body are unusually stiff and tend to contract (tighten) too strongly and too easily. This is sometimes called congenital muscle stiffness or generalized myotonia with hypercontractility, though the full syndrome name is the most precise term used by doctors today. The condition affects skeletal muscles — the muscles you use to move your body. When muscles contract too easily or stay contracted longer than normal, everyday movements like walking, gripping objects, or even blinking can feel stiff or slow, especially after rest. Warming up with gentle movement often helps loosen the muscles temporarily. Babies with this condition may appear unusually stiff or have feeding difficulties from birth. Treatment is focused on managing symptoms rather than curing the disease. Medications that calm overactive muscle electrical signals, along with physical therapy, are the main tools doctors use. Because this is an extremely rare condition, treatment plans are highly individualized and are best managed by a specialist team with experience in rare muscle diseases.

Key symptoms:

Widespread muscle stiffness from birthMuscles that tighten or cramp with movement, especially after restDifficulty relaxing muscles after gripping or squeezingStiffness that improves slightly with repeated movement (warm-up effect)Feeding difficulties in newborns due to stiff facial and jaw musclesDelayed motor milestones such as rolling over or sitting upMuscle pain or discomfort with activityStiff facial expression or difficulty with facial movementsDifficulty swallowing in some casesEpisodes of generalized muscle rigidity

Inheritance

Variable

Can be inherited in different ways depending on the underlying gene

Age of Onset

Neonatal

Begins at or shortly after birth (first 4 weeks)

Orphanet ↗NORD ↗

Treatments

No FDA-approved treatments are currently listed for Congenital generalized hypercontractile muscle stiffness syndrome.

View clinical trials →

No actively recruiting trials found for Congenital generalized hypercontractile muscle stiffness syndrome at this time.

New trials open frequently. Follow this disease to get notified.

Search ClinicalTrials.gov ↗Join the Congenital generalized hypercontractile muscle stiffness syndrome community →

No specialists are currently listed for Congenital generalized hypercontractile muscle stiffness syndrome.

View NORD Rare Disease Centers ↗Undiagnosed Disease Network ↗

Treatment Centers

8 centers
🏥 NORD

Baylor College of Medicine Rare Disease Center

Baylor College of Medicine

📍 Houston, TX

🏥 NORD

Stanford Medicine Rare Disease Center

Stanford Medicine

📍 Stanford, CA

🔬 UDN

NIH Clinical Center Undiagnosed Diseases Program

National Institutes of Health

📍 Bethesda, MD

🔬 UDN

UCLA UDN Clinical Site

UCLA Health

📍 Los Angeles, CA

🔬 UDN

Baylor College of Medicine UDN Clinical Site

Baylor College of Medicine

📍 Houston, TX

🔬 UDN

Harvard/MGH UDN Clinical Site

Massachusetts General Hospital

📍 Boston, MA

🏥 NORD

Mayo Clinic Center for Individualized Medicine

Mayo Clinic

📍 Rochester, MN

👤 Mayo Clinic Center for Individualized Medicine

🏥 NORD

UCLA Rare Disease Day Program

UCLA Health

📍 Los Angeles, CA

Travel Grants

No travel grants are currently matched to Congenital generalized hypercontractile muscle stiffness syndrome.

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Community

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Caregiver Resources

NORD Caregiver Resources

Support, advocacy, and financial assistance for caregivers of rare disease patients.

Mental Health Support

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Family & Caregiver Grants

Financial assistance programs specifically for caregivers of rare disease patients.

Social Security Disability

Learn how rare disease patients may qualify for SSDI/SSI benefits.

Questions for your doctor

Bring these to your next appointment

  • Q1.What genetic test should we do to confirm the diagnosis and find the specific gene involved?,Are there medications that can reduce my muscle stiffness, and what are the risks and benefits?,Are there any anesthesia or surgery risks I need to tell other doctors about?,What therapies — physical, occupational, or other — would help most at this stage?,Are there any clinical trials or research studies I could participate in?,What warning signs should prompt an emergency room visit?,Should other family members be tested for this condition?

Common questions about Congenital generalized hypercontractile muscle stiffness syndrome

What is Congenital generalized hypercontractile muscle stiffness syndrome?

Congenital generalized hypercontractile muscle stiffness syndrome is a very rare muscle disorder that is present from birth. The name describes the main problem: muscles throughout the body are unusually stiff and tend to contract (tighten) too strongly and too easily. This is sometimes called congenital muscle stiffness or generalized myotonia with hypercontractility, though the full syndrome name is the most precise term used by doctors today. The condition affects skeletal muscles — the muscles you use to move your body. When muscles contract too easily or stay contracted longer than norma

At what age does Congenital generalized hypercontractile muscle stiffness syndrome typically begin?

Typical onset of Congenital generalized hypercontractile muscle stiffness syndrome is neonatal. Age of onset can vary across affected individuals.