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Azorean Disease - Causes, Symptoms, Types, Risk, Diagnosis and Treatment

Published on Mar 17, 2022   -  4 min read


Azorean disease is a disorder that causes impaired brain function, vision problems, and abnormal muscle control. Learn more about the causes, symptoms, diagnosis, and treatment below.


What Is Ataxia?

Ataxia is a term that indicates loss of control or coordination of muscles during voluntary movements. Ataxia often occurs due to damage in the brain that controls muscle movement (cerebellum). Ataxia can affect various activities causing difficulty swallowing, eye movement, and speech or articulation disorder.

Conditions that cause ataxia are high alcohol consumption, stroke, cerebral palsy, intake of certain medications, brain degeneration, multiple sclerosis, and inherited defective genes. Treatment is given depending on the cause. Adaptive devices are used to maintain a person’s gait. Physical therapy, regular aerobic exercise, and speech therapy might help.

What Is Spinocerebellar Ataxia?

Spinocerebellar ataxia (SCA) is a term that refers to a group of hereditary ataxias showing degenerative changes in the brain that controls movement (cerebellum and spinal cord involvement in some cases). There are different types of SCA, which are classified according to the mutated gene responsible for the specific type of SCA.

What Is Azorean Disease?

Azorean disease is a disorder that causes impaired brain function, vision problems, and muscle control. It is named after a group of nine Portuguese islands called Azores, where the disease was prevalent. Azorean disease is otherwise known as spinocerebellar ataxia type III (SCA 3), Machado-Joseph disease (MJD), and Joseph disease.

This disease is classified into three types depending on their age of onset and physical symptoms. The age of onset is 25 years or less in type I. The affected person experiences muscle stiffness, awkward body movements, slow staggering gait, and slurred speech. Mental alertness and intellectual capacities remain unaffected.

Type II progresses at a slower rate when compared to type I. In type II, the age of onset is around 30 years. The distinctive symptom observed in type II is cerebellar dysfunction that results in an unsteady gait. The affected person may also experience progressive muscle loss, resulting in an inability to walk.

The average age of onset is 40 years or later in type III. This condition causes unsteady gait and is distinguished from other types by loss of muscle mass due to inflammation and degeneration of peripheral nerves. The other symptoms are weakness and reduced sensitivity to pain in the arms and legs. The progression of type III is slow when compared to other types.

The symptoms of the Azorean disease occur due to the loss of brain cells and impaired connections in the brain and spinal cord. The degradation of the central nervous system is caused by the production of a destructed protein from a mutated gene.

What Is the Cause of Azorean Disease?

Azorean disease is inherited as an autosomal dominant trait, which means that only one parent passes the gene mutation to their child. Each gene in the human body is made of nucleotides C (cytosine), A (adenine), T (thymine), and G (guanine). The sequence of three nucleotides is known as trinucleotide.

This Azorean disease is caused due to a gene mutation that results in over duplication of a CAG trinucleotide sequence. The location of the mutant gene in Azorean disease is 14q32, which is present on the long arm of chromosome 14. Usually, this gene encodes the formation of a protein called ataxin-3.

Around 13 and 36 repetitions occur in the CAG sequence of the general population. In individuals affected with Azorean disease, approximately 61 and 84 repetitions occur. This increased number of genes encodes an abnormal protein responsible for cell death in the brain and spinal cord.

In successive generations, these repetitions may increase and cause genetic anticipation. Suppose the individual is homozygous for the mutated gene, which means the individual inherits the gene from both parents, Azorean disease occurs severely, and the age of onset is early at 16 years.

What Are the Symptoms of Azorean Disease?

The first observable symptom of Azorean disease is difficulty walking and slurred speech. Poor muscle coordination in the eyes and other physical problems also occur.

The muscular symptoms observed in Azorean disease are weakness in the arms or legs, involuntary jerking, cramping in hands and feet, and twitching in the facial muscles. People affected with the Azorean disease may also experience double vision, bulging eyes, difficulty looking upward and opening eyes, and involuntary eye movements from side to side.

The other symptoms observed are difficulty speaking, loss of feeling in the arms and legs, frequent urination, diabetes, lung infection, weight loss, and difficulty sleeping.

How to Diagnose Azorean Disease?

This disease is diagnosed after observing the typical symptoms in the affected person. Brain imaging studies such as computed tomography (CT) and magnetic resonance imaging (MRI) are also done.

Genetic studies provide definitive confirmation for the diagnosis of Azorean disease. This study shows an increased number of CAG trinucleotide repeats in the affected individual. Blood tests show increased levels of blood sugar and uric acid.

The symptoms of the Azorean disease occur similar to other degenerative neurological conditions such as Parkinson's disease, Huntington's disease, and multiple sclerosis. Careful diagnosis is necessary to distinguish this Azorean disease from other health issues.

How to Treat Azorean Disease?

Treatment for the Azorean disease is given based on the symptoms. There is no specific treatment to reverse the effects of this disease. Dopamine agonists help to reduce some signs of the Azorean disease. Some experimental drugs and medicines under development may provide some benefits. As this Azorean disease is an inherited disorder, genetic counseling is required for people having a family history of this disease.

What Is the Prognosis of the People Affected With Azorean Disease?

The prognosis of the affected individuals varies depending on the age of onset and severity of symptoms. The muscular degeneration caused by this disease results in eventual confinement and use of a wheelchair in the affected person. After the onset of symptoms, the life expectancy of the affected individual is around 10 to 30 years.


Azorean disease is a disorder that causes impaired brain function, vision problems, and muscle control. If you experience any of the symptoms mentioned above, consult a healthcare provider at the earliest to rule out Azorean disease or get a prompt treatment plan.

To know more information and treatment for the Azorean disease, consult a doctor at

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17 Mar 2022  -  4 min read




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