Disease Directory Kennedy Disease
Neuromuscular

Kennedy Disease

Also known as: SBMA, spinal and bulbar muscular atrophy, X-linked bulbospinal neuropathy

Prevalence

1 in 40,000 males

Onset

Adult males, typically 3rd–5th decade

Type

X-linked recessive (trinucleotide repeat expansion)

Gene

AR

About Kennedy Disease

Kennedy Disease, or Spinal and Bulbar Muscular Atrophy, is an X-linked motor neuron disease caused by a CAG trinucleotide repeat expansion in exon 1 of the androgen receptor (AR) gene, resulting in toxic gain-of-function of the mutant polyglutamine-expanded AR protein in motor neurons and muscles. It affects only males (females are carriers) and is characterised by progressive limb and bulbar muscle weakness, androgen insensitivity features, and sensory neuronopathy. Disease progression is slow compared to ALS.

Common Clinical Features

Slowly progressive proximal limb muscle weakness Bulbar dysfunction (dysarthria, dysphagia, tongue fasciculations) Gynecomastia and reduced fertility (androgen insensitivity) Postural tremor of the hands Muscle cramps and fasciculations Sensory abnormalities (reduced vibration sense) Elevated serum creatine kinase

Clinical Trial Eligibility Tips

What to know before applying to Kennedy Disease trials.

Genetic confirmation of CAG repeat length in the AR gene (≥38 repeats) is required; repeat length correlates inversely with age of onset and may be a stratification variable in trials

Testosterone levels are frequently collected as a pharmacodynamic biomarker; baseline hormonal profile including LH, FSH, and testosterone should be documented

SBMA Functional Rating Scale (SBMAFRS) and 40-metre walk test are standard clinical endpoints; formal neuromuscular assessment documentation strengthens your application

Patient Resources

Patient Organization

Kennedy's Disease Association

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Natural History Registry

KDA Patient Registry

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Orphanet

European reference resource for rare diseases (ORPHA:481)

View on Orphanet ↗

NORD

National Organization for Rare Disorders

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Find recruiting Kennedy Disease trials

Search 500,000+ studies from ClinicalTrials.gov, filtered for Kennedy Disease. Updated daily.

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