Spinal muscular atrophy with respiratory distress type 2

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ORPHA:404521G12.2
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1Specialists8Treatment centers

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UniteRare data is sourced from FDA.gov, ClinicalTrials.gov, Orphanet, OMIM, and NORD.
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Overview

Spinal muscular atrophy with respiratory distress type 2 (SMARD2) is an extremely rare genetic condition that affects the nerves controlling muscles, particularly those involved in breathing. It belongs to a group of diseases called spinal muscular atrophies, which cause progressive muscle weakness due to the loss of motor neurons — the nerve cells in the spinal cord that send signals to muscles. In SMARD2, the breathing muscles (especially the diaphragm) are severely affected, leading to serious breathing difficulties that often appear early in life. Babies and young children with this condition may develop weakness in the arms and legs, have trouble feeding, and experience life-threatening respiratory failure. SMARD2 is caused by mutations in the LAS1L gene, which is located on the X chromosome. This means the condition follows an X-linked pattern of inheritance and primarily affects males, though females can sometimes show milder symptoms. The disease is distinct from the more commonly known forms of spinal muscular atrophy (SMA types 1-4), which are caused by mutations in the SMN1 gene. Currently, there is no cure for SMARD2. Treatment focuses on managing symptoms, especially supporting breathing through mechanical ventilation, and providing nutritional support. Physical therapy and rehabilitation may help maintain some muscle function. Because this condition is so rare, research is still ongoing to better understand the disease and develop targeted therapies.

Also known as:

Key symptoms:

Severe breathing difficulties due to diaphragm weaknessMuscle weakness in arms and legsPoor muscle tone (floppy baby)Difficulty feeding or swallowingWeak cryFailure to thrive or poor weight gainReduced or absent reflexesRespiratory failure requiring ventilationMuscle wasting (atrophy)Limited movement of limbsRecurrent lung infectionsIntellectual disability in some cases

Inheritance

X-linked recessive

Carried on the X chromosome; typically affects males more than females

Age of Onset

Neonatal

Begins at or shortly after birth (first 4 weeks)

Orphanet ↗NORD ↗

Treatments

No FDA-approved treatments are currently listed for Spinal muscular atrophy with respiratory distress type 2.

View clinical trials →

No actively recruiting trials found for Spinal muscular atrophy with respiratory distress type 2 at this time.

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

Search ClinicalTrials.gov ↗Join the Spinal muscular atrophy with respiratory distress type 2 community →

Specialists

1 foundView all specialists →
CP
Chiara Marini-Bettolo, MD, PhD
Newcastle upon Tyne
Specialist

Rare Disease Specialist

PI on 3 active trials

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 Spinal muscular atrophy with respiratory distress type 2.

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Community

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Latest news about Spinal muscular atrophy with respiratory distress type 2

5 articles
PolicyRSSApr 24, 2026
Newborn SMA screening widely supported in U.K. survey
A large survey in the U.K. found that most people—including families of babies screened for SMA, people living with SMA, doctors, and the general public—strongl
NewsRSSApr 23, 2026
Managing intense knee pain after a fall onto a concrete floor
A person with SMA (spinal muscular atrophy) experienced a serious fall onto concrete while their nurse was helping them get dressed, resulting in intense knee p
ResearchRSSApr 22, 2026
Targeting JNK pathway may offer new treatment approach for SMA
Scientists discovered that blocking a protein pathway called JNK in the body may help treat spinal muscular atrophy (SMA), a disease that weakens muscles. In mi
NewsRSSApr 22, 2026
Having the newest generation of technology isn’t just a luxury with SMA
A person living with SMA (spinal muscular atrophy) discusses how having up-to-date technology is important for their daily life and work, not just a luxury. The
NewsRSSApr 22, 2026
My recent overnight sleep study was uncomfortable, but necessary
The author shares their personal experience undergoing an overnight sleep study, comparing it to a previous study from 2002. They describe feeling nervous about
See all news about Spinal muscular atrophy with respiratory distress type 2

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 type of breathing support will my child need, and how will this change over time?,Are there any clinical trials or experimental treatments available for SMARD2?,What is the expected course of this disease for my child specifically?,How should we handle respiratory infections or emergencies at home?,What feeding support options are available, and when should we consider a feeding tube?,Should other family members be tested for carrier status of the LAS1L gene mutation?,What palliative care and family support services are available to us?

Common questions about Spinal muscular atrophy with respiratory distress type 2

What is Spinal muscular atrophy with respiratory distress type 2?

Spinal muscular atrophy with respiratory distress type 2 (SMARD2) is an extremely rare genetic condition that affects the nerves controlling muscles, particularly those involved in breathing. It belongs to a group of diseases called spinal muscular atrophies, which cause progressive muscle weakness due to the loss of motor neurons — the nerve cells in the spinal cord that send signals to muscles. In SMARD2, the breathing muscles (especially the diaphragm) are severely affected, leading to serious breathing difficulties that often appear early in life. Babies and young children with this condit

How is Spinal muscular atrophy with respiratory distress type 2 inherited?

Spinal muscular atrophy with respiratory distress type 2 follows a x-linked recessive inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.

At what age does Spinal muscular atrophy with respiratory distress type 2 typically begin?

Typical onset of Spinal muscular atrophy with respiratory distress type 2 is neonatal. Age of onset can vary across affected individuals.

Which specialists treat Spinal muscular atrophy with respiratory distress type 2?

1 specialists and care centers treating Spinal muscular atrophy with respiratory distress type 2 are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.