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Hope Dignity Awareness
Huntington’s Victoria is the leading specialist service that supports individuals impacted by Huntington’s disease.

Understanding HD

Every one of us carries the Huntingtin gene which assists nerve cells in functioning effectively. For some of us, the gene is faulty, leading to Huntington’s disease – a fatal genetic condition. This disease does not discriminate between race, gender, ethnicity and age. While this devastating disease might not be well known within the wider community, it is not rare. It could affect someone you know.

What is HD?
Juvenile HD
The Genetics of HD
Who is affected?
Diagnosis

What is HD?

Huntington’s Disease (HD) results in brain cell death and affects the basal ganglia and frontal lobe regions of the brain. These regions are responsible for motor movement control and coordination, cognition, personality and emotions. Deterioration in these regions of the brain results in significant impairments in one’s ability to think, feel and move. HD onset predominantly occurs in young-middle adulthood (35– 50years). 

Juvenile HD

There is a juvenile form of Huntington’s disease that presents before the age of 20 and, although rare, it is more rapidly progressive. 


The Genetics of HD 

Huntington's gene family

Our body consist of 23 pairs of chromosomes, 22 pairs of autosomes and 1 pair of sex chromosomes. Chromosomes are made of long strands of genes which are the basic unit of inheritance. We inherit one chromosome from our mother and one from our father (see diagram). The gene of Huntington’s disease (HD) is located on chromosome 4. People with HD have one ‘working’ copy of the gene and one ‘faulty’ copy. When they have children, they may pass on the ‘working’ copy or the ‘faulty’ one, giving each child a 50% chance of inheriting the faulty gene. If you inherit the faulty gene from your affected parent, at some stage, you will develop the symptoms of HD.  If you inherit the working gene, then you won’t get the disease and none of your children will inherit the gene and develop HD.


Who is affected?

Being a genetic disease, each child of a parent with HD has a 50% chance of inheriting the defective Huntingtin gene. HD both directly and indirectly affects the following:

  • Diagnosed with Huntington’s disease - this is someone who has been formally diagnosed and is showing symptoms (symptomatic)

  • Tested gene positive after predictive testing - this is someone who is not symptomatic or fomally diagnosed but will eventually develop symptoms of HD

  • At-risk of developing Huntington’s disease - this is someone with a parent who has HD but has not been tested or diagnosed

  • Tested gene negative after predictive testing - this is someone who has been tested and does not carry the faulty gene
     
  • Carers of persons identified above

A gene test is available which allows a person at risk to find out if they carry the faulty HD gene and will someday develop the disease. You can find more information about predictive testing here.


Diagnosis 

In order to receive a diagnosis, you will need to obtain a referral from your GP to see a HD specialist. Consultation(s) with a specialist is covered by Medicare. The initial consultation may include:

  • Discussion of family history
  • Your current knowledge of HD
  • Discussion of symptoms you believe to be exhibiting
  • Neurological/cognitive examination (body movement, reflexes, memory etc.)
  • Assessment of mental and emotional state

After the above assessments, the specialist will inform you of whether or not they believe you are exhibiting symptoms of HD. The specialist will require a blood test to confirm that your symptoms are associated with HD.


Resources:

ACAH

Accredited by the Australian Council on Healthcare Standards until 15/07/2017

ACAH