NEW: DNA testing for SBMA (Spinobulbar muscle atrophy, aka Kennedy's disease)

The SBMA test is a genetic test aimed at detecting spinobulbar muscle atrophy (SBMA), also known as Kennedy's disease. This rare, inherited disorder affects muscle and nerve tissue and occurs almost exclusively in men. The test analyzes the androgen receptor (AR) gene on the X chromosome for an abnormal CAG repeat, which is characteristic of SBMA.

In healthy individuals, the number of repeats of the DNA motif CAG in the AR gene is limited. In SBMA patients, this number of repeats is greatly increased, leading to the production of an aberrant androgen receptor protein. This protein gradually causes damage to motor nerve cells, resulting in progressive muscle weakness.

This genetic test examines:

• The length of the CAG repeat in the AR gene (X-chromosomal).

The test shows whether there is a pathogenic CAG-repeat expansion that may be the cause of SBMA. In addition to diagnosing symptoms, this test is also suitable for family members of a patient to determine carrier status.

This test is particularly suitable for:

• Men with symptoms such as muscle weakness, muscle cramps, swallowing problems or breast formation (gynecomastia)
• Female relatives of a patient (such as mothers, sisters or daughters), because of X-linked inheritance

Early diagnosis is important for recognizing the disease and initiating targeted counseling. Although there is no curative treatment yet, knowledge of the genetic cause can contribute to better care and support.

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