Limb-Girdle Muscular Dystrophy, Type 2A

Gene : CAPN3

What is limb-girdle muscular dystrophy type 2A?

Limb-girdle muscular dystrophy includes a group of inherited disorders that cause muscle weakness and decreased amount of skeletal muscle involving the muscles around the hips and shoulders. This causes unusual walking gait, difficulty running, and usually eventual loss of the ability to walk. Onset of the disorder, progression rate and distribution of weakness are variable among the different subtypes of this disorder. Most individuals affected with limb-girdle muscular dystrophy type 2A (LGMD2A) start showing signs of muscle weakness in childhood and are wheelchair bound in 11-28 years after onset. Affected people may experience protruding of the shoulder blade, joint stiffness, and overgrowth of the calf muscles. Intellect is generally not affected. There is no cure for LGMD2A; however medical surveillance and care may help to improve some symptoms and overall condition of life. LGMD2A is caused by pathogenic variants in the CAPN3 gene.

How is limb-girdle muscular dystrophy type 2A inherited?

LGMD2A is inherited in an autosomal recessive manner. This type of inheritance requires the presence of two copies of a pathogenic variant in the gene for a person to have the genetic disease. Both parents must be carriers of a pathogenic variant in the gene in order to be at risk to have an affected child. The child must inherit a pathogenic variant from each carrier parent in order to be affected. There is a 1 in 4 chance that a baby will inherit two mutated copies of the gene and be affected when both parents are carriers.

What does it mean to be a carrier?

There are generally no signs or symptoms associated with being a carrier for LGMD2A. However, the risk to have a child affected with LGMD2A is increased. Testing of reproductive partners is recommended for carriers of LGMD2A.

How common is limb-girdle muscular dystrophy type 2A?

The occurrence of all forms of Limb-girdle muscular dystrophy is estimated to be 1 in 14,500 to 1 in 123,000 newborns.

Family References and Resources
Clinician References
What is Analyzed?
  • Full gene sequencing
Affected Systems



Carrier Rates
Detection Rate
Carrier Frequency
East Asian 85% 1 in 232
General Population 89% 1 in 602
Northern European Caucasian 89% 1 in 103

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