Health conditions

Genetic conditions

What is a genetic condition?

A genetic condition occurs when you inherit an altered (changed) gene from your parents that increases your risk of developing that particular condition. However not all genetic conditions are passed down from your parents, some gene changes occur randomly before you are born.

Many health conditions run in families. Genetic conditions are often called hereditary because they can be passed from parents to their children.

Examples of genetic conditions include:

  • some cancers
  • cystic fibrosis
  • high cholesterol
  • haemophilia
  • muscular dystrophy
  • birth defects (for example, spina bifida or a cleft lip).

Find out more about how your family’s health history can increase your risk of getting some conditions.

What are genes?

Your genes contain the information your body uses to control how you grow, develop and function. They determine most of your physical characteristics, including:

  • whether you are male or female
  • blood type
  • eye colour
  • height.

Many health conditions and diseases are also carried in our genes.

Your genes are contained in a number of packages called chromosomes. You have 23 pairs of chromosomes, 46 in total. Changes in your chromosomes, such as having more than 46, can also cause genetic conditions like Down Syndrome.

How your genes affect your health

Almost all known conditions have a genetic basis. For example:

  • around 5 per cent of cancers are passed down through families
  • early onset of conditions such as Alzheimer’s disease, cancer and osteoporosis are often because there is a family history of the condition.

Your environment also interacts with your genes to increase the risk of conditions such as diabetes, asthma and autoimmune disorders.

Social changes, such as women having children later in life, are also associated with:

  • an increased number of pregnancies at risk of genetic conditions and birth defects
  • increased need for pregnancy screening and diagnostic tests.

How common are genetic conditions?

Approximately 6 out of 10 people will be affected by a condition which has some genetic background. Genetic conditions can range from mild to very severe.

Genetic conditions and birth defects occur in between 3 and 5 per cent of babies born in Western Australia.

Testing for genetic conditions

Genetic tests can be used to:

  • confirm or rule out a suspected genetic condition
  • assess your chance of developing or passing on a genetic condition.

Find out more about the different types of genetic tests.

The role of genetics

In general, genetics play a role in the development of disease in three main ways:

  • Firstly, there can be changes or alterations to the DNA of particular genes – these are known as Mendelian or single gene disorders.
  • Secondly, there may be problems with the number or the structure of the chromosomes that are inherited from each parent – these are Chromosomal disorders.
  • And thirdly, our genes interact with various environment and lifestyle factors to cause disease – these are Multifactorial or complex disorders.

Visit the Genetics Home Reference (external site) for more information.

Where to get help


  • Many health conditions run in families.
  • Your genes contain the information your body uses to control how you grow, develop and function.
  • A genetic condition can be passed down through your family, increasing the risk of family members developing a condition.


Office of Population Health Genomics

This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.

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