What is Machado-Joseph disease (MJD) or spinocerebellar ataxia type 3 (SCA3)?
MJD is an adult onset neurological disease that begins between ages 20-50 years. The main symptoms are those of instability and reduced coordination (cerebellar ataxia), eye movement limitation (external ophthalmoplegia), difficulty in speech and swallowing (dysarthria and dysphagia), rigidity and weakness of limb muscles, and impaired sensation due to neuropathy. The severity and the particular symptoms’ combination may differ but the disorder causes marked disability.
MJD is a hereditary disease cause by an expansion of a gene called ATXN3. This mutation is transmitted in a dominant fashion (i.e. one affected parent may transmit it to an offspring with a 50% chance for each) and can be identified by a molecular test in a blood sample. The disease is prevalent mainly in people of Portuguese ancestry but has been recorded worldwide. Currently there is no effective therapy for this condition.
Patient Support
Genetic Home reference (NIH):
http://ghr.nlm.nih.gov/con…
National Ataxia Foundation:
Orphanet:
http://www.orpha.net/conso…
Living with ataxia online support group:
Publications
Toward understanding Machado-Joseph disease:
http://www.ncbi.nlm.nih.gov/pu…
Aggregate-prone proteins are cleared from the cytosol by autophagy: therapeutic implications:
http://www.ncbi.nlm.nih.gov/pub…
Machado-Joseph Disease: from first descriptions to new perspectives:
http://www.ojrd.com/con…
SCA3: neurological features, pathogenesis and animal models:
http://www.ncbi.nlm.nih.gov/pu…
Spinocerebellar Ataxia Type 3- Gene review:
http://www.ncbi.nlm.nih.gov/b…
Spinocerebellar ataxias caused by polyglutamine expansions: a review of therapeutic strategies:
http://www.ncbi.nlm.nih.gov/pu…