Think you have Kennedy's Disease? 

Kennedy's disease (Spinal Bulbar Muscular Atrophy) is an X-linked recessive disorder. A blood test will confirm whether an individual possesses the spinal and bulbar muscular atrophy (SBMA) CAG mutation and therefore is likely to be affected with a predisposition to developing the clinical symptoms associated with Kennedy's Disease. Some of the clinical symptoms associated with Kennedy's disease are listed below. If you are interested in labs that can perform the SBMA test, please click here. 

Medical Term:




Bulbar Signs   The Bulbar muscles are those supplied by the motor nerves coming off the brain stem which control breathing, swallowing, talking and other functions of the throat. Bulbar signs are problems with these functions.


  Trouble swallowing. (One of the Bulbar signs.)
Intention Tremor   Hand tremors when trying to do something.
Normal Babinski   Normal plantar response, ie., when the bottom of the foot is scraped, the toes bend down. An abnormal response would be an upward bending of the toes indicating a problem in the brain itself.

Lower Motor Neuropathy

  The lower motor nerves are those that run from the spinal cord to the muscles that they stimulate to move. Loss of that nerve leads to weakness and wasting of the muscle.
Primary Sensory Neuropathy   Numbness over certain areas. Loss of sensation.

Decreased or Absent Deep Tendon Reflexes

  When a doctor taps the knee with his hammer there is no response.


Fasciculations   Twitching of small muscles without purposeful movement, that can be seen through the skin.
Cramps   Large muscle spasms.
Postural Tremor   Shaky muscles with certain positions.
Muscular Atrophy   Wasting and shrinkage of muscles that occurs when the lower motor nerve does not stimulate the muscle adequately.

Hypertrophied Calves

  Calf muscles that become thicker because of cramps.




  Enlarged breasts.


Androgen Deficiency   Loss of masculinizing effect.

Estrogen Excess

  More of an apparent estrogen effect because of the lost of masulinizing effect.


Impotence   Erectile dysfunction.
Reduced Fertility   Low sperm count.

Testicular Atrophy

  Testicles become smaller and less functional.

 Miscellaneous Characteristics:

Late Apparent Onset   Symptoms could become apparent in 20's or 30's, but might not appear until the 60's or 70's.
Slow Progression   Near-normal lifespan.

Asymmetry of Clinical Signs

  Muscles of one side may be more affected than the same muscles on the other side.


Elevated Serum Creatine Kinase   Elevation of CPK enzyme in the blood test.  Can be confused with the enzyme released during a heart attack.
Genetic Test  

DNA Test: The Kennedy's Disease gene can be found in the blood by a genetic laboratory test in both affected males and carrier females. Detects CAG triplet repeat expansion in the androgen receptor gene.