Limb-Girdle Muscular Dystrophy, Type 2D

Gene : SGCA

What is limb-girdle muscular dystrophy type 2D?

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 2D (LGMD2D) start showing signs of muscle weakness in early childhood and are wheelchair bound in about 15 years after onset. Others have milder disease with onset in adolescence or adulthood. This disorder may cause weakening of heart muscles in some people. They may also develop joint and spine deformities. Intellect is generally not affected. Life span may be affected by severity of muscle weakness; as muscles deteriorate, respiratory function may decrease leading to early death as a result of respiratory failure. There is no cure for LGMD2D; however medical surveillance and care may help to improve some symptoms and overall condition of life. LGMD2D is caused by pathogenic variants in the SGCA gene.

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

LGMD2D 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 LGMD2D. The risk to have a child affected with LGMD2D is increased. Testing of reproductive partners is recommended for carriers of LGMD2D.

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

The occurance of all forms of Limb-girdle muscular dystrophy is estimated to be 1 in 14,500 to 1 in 123,000 newborns. The exact incidence for LGMD2D is unknown.

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

Muscle

Bone

Heart

Carrier Rates
Ethnicity
Detection Rate
Carrier Frequency
General Population 97% 1 in 160
Northern European Caucasian 97% 1 in 160

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