SBMA: Spinal Bulbar Muscular Atrophy

What is SBMA?

Spinal bulbar muscular atrophy ; which is basically weakness in motor neurons, voluntary system or it can be said neurodegenerative disorder .

This syndrome is popularly known as “Kennedy’s disease” , after the name of the scientist William R. Kennedy who discovered this disease in 1968.

Because of AR gene(androgen receptor) mutation which is inherent through X- linked recessive and that’s why also called as AIS- androgen insensitivity syndrome. And SBMA also relate to Huntington’s disease.

Let’s know more about its symptoms, cures and how it can be diagnosed

Symptoms

First of all this these symptoms appear after the age of 30 so don’t panic, it’s very rare in youngsters and adults.

Weakness of tongue muscle, limb muscle, spinal muscles
Muscle cramps
Respiratory musculature weakness
High weakness in bulbar muscles which control swallowing, speech, and other functions of throat
Deceased deep tendon reflexes
Gynecomastia
Erectile dysfunction
Reduced fertility

Diagnosis

SBMA – By measuring number of CAG repeats on AR gene which can be detected with 100% accuracy by using PCR method.

Treatment

There is no cure for this syndrome yet. But there are supportive management such as rehabilitation to improve muscles weaknesses.

Surgery may achieve corrections of the spine, but early surgical intervention should be done in cases where prolonged survival is expected.

Genetics behind this

It’s known that this syndrome is a hereditary syndrome. The X -chromosome where AR gene undergo mutation involves CAG repeats. These CAG repeats can be differ among individuals.

34 repeats – healthy

35 to 46 repeats – gradually increase

47 & above – 100% high risk

Life Expectancy;

10 to 15 years.