X-linked spinal muscular atrophy

Common Name(s)

X-linked spinal muscular atrophy, Arthrogryposis Multiplex Congenita Distal X-Linked, XLSMA, AMCX1

X-linked spinal muscular atrophy (XL-SMA) is one type of a group of conditions known as spinal muscular atrophies (SMAs), which are inherited disorders that cause muscle weakness and a loss of muscle tissue (atrophy). Symptoms of XL-SMA are usually present at birth and include low muscle tone (hypotonia), abnormal or absent reflexes (areflexia), abnormal muscle shortening that causes stiff joints (contractures), and broken bones (fractures). As the disease becomes worse with time (progresses), the muscles in the chest become weak, causing significant feeding and breathing problems. This is a serious condition that shortens the lifespan of most affected children.

XL-SMA is due to a change (mutation) in the UBE1 gene, which leads to a loss of specialized cells (lower motor neurons). The lower motor neurons are responsible for carrying signals from the brain to the muscles of the body. When the UBE1 gene is mutated, it causes the lower motor neurons to die off, leading to the muscle weakness and atrophy in this condition. XL-SMA is inherited in an X-linked recessive way, which means males are primarily affected. Males have one X chromosome (one copy of the UBE1 gene) while females have two X chromosomes (two copies of the UBE1). If a male has a mutation in their only copy, they will have XL-SMA. If females have a mutation in one of their two copies, it is not enough to cause the condition. Unaffected females with one mutation are called carriers and they are at risk of having an affected male child.

The diagnosis of XL-SMA is considered in a baby who is born with severe muscle weakness, contractures, and fractures. Genetic testing is used to confirm the diagnosis. Current treatment options are aimed at managing the symptoms of XL-SMA, including feeding and breathing support. If your child has been diagnosed with XL-SMA, talk with a doctor about all treatment options. Support groups are also available for additional information.

Source: Advocacy organizations associated with the condition.

 

Advocacy and Support Organizations

 

Condition Specific Organizations

Following organizations serve the condition "X-linked spinal muscular atrophy" for support, advocacy or research.

Thisbe and Noah Scott Foundation, Inc.

It is the mission of the Thisbe and Noah Scott Foundation, Inc. to save lives by promoting research, awareness and support for children and families affected by pediatric neuromuscular diseases.

Last Updated: 19 May 2015

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General Support Organizations

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Advocacy and Support Organizations

 

Condition Specific Organizations

Following organizations serve the condition "X-linked spinal muscular atrophy" for support, advocacy or research.

Thisbe and Noah Scott Foundation, Inc.

It is the mission of the Thisbe and Noah Scott Foundation, Inc. to save lives by promoting research, awareness and support for children and families affected by pediatric neuromuscular diseases.

http://www.thisbeandnoah.org/

Last Updated: 19 May 2015

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General Support Organizations

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Scientific Literature

Articles from the PubMed Database

Research articles describe the outcome of a single study. They are the published results of original research.
The terms "X-linked spinal muscular atrophy" returned 6 free, full-text research articles on human participants. First 3 results:

Tremor in X-linked recessive spinal and bulbar muscular atrophy (Kennedy's disease).
 

Author(s): Francisco A Dias, Renato P Munhoz, Salmo Raskin, Lineu César Werneck, Hélio A G Teive

Journal: Clinics (Sao Paulo). 2011 ;66(6):955-7.

 

To study tremor in patients with X-linked recessive spinobulbar muscular atrophy or Kennedy's disease.

Last Updated: 2 Aug 2011

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Rare missense and synonymous variants in UBE1 are associated with X-linked infantile spinal muscular atrophy.
 

Author(s): Juliane Ramser, Mary Ellen Ahearn, Claus Lenski, Kemal O Yariz, Heide Hellebrand, Michael von Rhein, Robin D Clark, Rita K Schmutzler, Peter Lichtner, Eric P Hoffman, Alfons Meindl, Lisa Baumbach-Reardon

Journal: Am. J. Hum. Genet.. 2008 Jan;82(1):188-93.

 

X-linked infantile spinal muscular atrophy (XL-SMA) is an X-linked disorder presenting with the clinical features hypotonia, areflexia, and multiple congenital contractures (arthrogryposis) associated with loss of anterior horn cells and infantile death. To identify the XL-SMA disease ...

Last Updated: 8 Jan 2008

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Loss of endogenous androgen receptor protein accelerates motor neuron degeneration and accentuates androgen insensitivity in a mouse model of X-linked spinal and bulbar muscular atrophy.
 

Author(s): Patrick S Thomas, Gregory S Fraley, Vincent Damian, Vincent Damien, Lillie B Woodke, Francisco Zapata, Bryce L Sopher, Stephen R Plymate, Albert R La Spada

Journal: Hum. Mol. Genet.. 2006 Jul;15(14):2225-38.

 

X-linked spinal and bulbar muscular atrophy (SBMA; Kennedy's disease) is a polyglutamine (polyQ) disease in which the affected males suffer progressive motor neuron degeneration accompanied by signs of androgen insensitivity, such as gynecomastia and reduced fertility. SBMA is caused ...

Last Updated: 28 Jun 2006

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Reviews from the PubMed Database

Review articles summarize what is currently known about a disease. They discuss research previously published by others.
The terms "X-linked spinal muscular atrophy" returned 0 free, full-text review articles on human participants.

 
 
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Symptoms, Diagnosis, and Treatment

There are currently no related results available in Genetics Home Reference.

 
 
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Clinical Trial Information This information is provided by ClinicalTrials.gov

Genetics of Pediatric-Onset Motor Neuron and Neuromuscular Diseases
 

Status: Recruiting

Condition Summary: Spinal Muscular Atrophy; Charcot-Marie-Tooth Disease; Muscular Dystrophy; Spinal Muscular Atrophy With Respiratory Distress 1; Amyotrophic Lateral Sclerosis; Motor Neuron Disease; Neuromuscular Disease; Peroneal Muscular Atrophy; Fragile X Syndrome

 

Last Updated: 24 Aug 2015

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Effects of Standing on Non-Ambulatory Children With Neuromuscular Conditions
 

Status: Recruiting

Condition Summary: Osteopenia; Spinal Muscular Atrophy; Cerebral Palsy; Muscular Dystrophy; Spina Bifida; Rett Syndrome

 

Last Updated: 8 Aug 2016

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Flu Vaccine Study in Neuromuscular Patients 2011
 

Status: Recruiting

Condition Summary: Duchenne Muscular Dystrophy; Spinal Muscular Atrophy; Congenital Muscular Dystrophy

 

Last Updated: 22 Aug 2011

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