Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

DNA structure

DNA structure
beginning of content

Guide to genetic disorders

5-minute read

Genes are one of the basic units of life. Problems with genes can cause health or development problems. Some genetic disorders affect people from birth, others develop later in life. If you are concerned that you or someone you care for has, or might have, a genetic disorder, this page will provide you with more information.

Where are genes made of?

Almost every cell in the body has a centre called a nucleus. In almost every nucleus, there are 46 chromosomes. Chromosomes are passed from parent to child, and are the vehicle for carrying all that a child inherits from their parents.

Chromosomes are made of a chemical compound called DNA (deoxyribose nucleic acid). A gene is a small section of that DNA. There are more than 20,000 genes in the human body.

How do genes influence your life?

Genes contain the recipes for who you are, and they influence your life from the moment you are conceived. They have a strong influence over how you look and the colour of your eyes, hair and skin.

But genes don't switch off the moment you're born. They also play a part in your personality and how you think about the world. They continue to influence your health and wellbeing for as long as you live.

They do this by instructing the body to produce the proteins that are used by cells. These proteins will help you to do things such as grow, digest food and think. Some will help protect you against cancer, while others will allow cancer to grow.

The way your genes work can be influenced by many different things, such as your way of life or the environment around you. This field of knowledge is known as epigenetics.

What's a genetic disorder?

A genetic disorder is a health condition that comes about because of a problem with a gene or with a chromosome.

A problem with a single gene is known as a gene mutation. You can have a gene mutation without it causing any problems. But some gene mutations can cause problems such as cystic fibrosis, Huntington's disease and haemophilia.

If you have a problem with a chromosome, that will probably cause noticeable problems. Some people have a missing chromosome, some have an extra chromosome, some have a broken chromosome. Down syndrome, Turner syndrome and Klinefelter syndrome are all examples of chromosomal disorders.

Why do genetic disorders occur?

Most genetic disorders occur by chance. Genes and chromosomes are complex, and they often get changed slightly in the formation of new life.

Some disorders are passed down from a parent. If a parent has a damaged gene or chromosome, and that is passed down to a child, the child's health might be affected.

Others come about through changes in a person's DNA during their life. For example, radiation from the sun can damage a person's DNA in a way that it allows skin cancer to develop.

Are genetic disorders always inherited?

Many genetic disorders are inherited, but many others are not. Some occur simply because a piece of genetic material was damaged as it was being passed from parent to child. In that case, a child can have a genetic disorder that the parent does not have. The damage to the gene is known as a spontaneous mutation.

Do genetic disorders always show up in babies?

No. Some genetic conditions can be seen from birth. Others show up during childhood, adolescence or adult life.

How are genetic disorders diagnosed?

Some genetic disorders can be tested for. There are many issues to consider before having genetic testing, such as the effect of a test on other family members or whether having a test might affect your working conditions or your chances of getting insurance. You should not have genetic testing without thinking it through carefully.

If you want to discuss testing, it is worth starting with your family doctor or a genetic counsellor. A genetic counsellor is an expert in working with families to discuss genetic conditions. They can talk to you about whether testing is available, the benefits and risks of testing, about privacy and confidentiality, about work and insurance, and about talking to members of your family. They generally work with other experts in genetics.

Some testing is available online or without the involvement of a health professional. The National Health and Medical Research Council warns that people should be cautious of this

Learn more about genetic testing.

Where to go for help?

If you want to try to prevent genetic disorders that run in your family, or if you want to try to detect any possible genetic conditions, it is best to talk to either your doctor or a genetic counsellor. To find a genetic counsellor, go to the Australian Society for Genetic Counsellors.

If you have a genetic condition in your family, there are many support groups you can join. Some meet in person while others operate online or by telephone. You can find some listed by the Human Genetics Society of Australia, and you can find others by searching for the condition you are concerned with.

More information

The NSW Centre for Genetics Education is a good source of more detailed information on genetic disorders and services.

If you're pregnant or thinking about having a child, see Pregnancy, Birth and Baby's information on genetic counselling or call the helpline on 1800 882 436.

If you or someone you care for has a rare genetic condition, you may be able to find a support group through Genetic Alliance Australia.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: July 2020

Back To Top

Need more information?

These trusted information partners have more on this topic.

Top results

Learn more about rare diseases including genetic disorders

An estimated two million Australians live with a rare disease, many of these conditions are genetic disorders.

Read more on Rare Voices Australia website

Genomics explainer: genotype and phenotype | Garvan Institute of Medical Research

A person’s genotype is their unique sequence of DNA. More specifically, this term is used to refer to the two forms a person has inherited from their mother and father, for a particular gene.

Read more on Garvan Institute of Medical Research website

Syndromes without a name: children & teens | Raising Children Network

SWAN means syndromes without a name. Doctors might use the term SWAN when children have symptoms of genetic disorder but the symptoms can’t be diagnosed.

Read more on website

Genetic counselling

Genetic counselling may be recommended for people who have a history of hereditary disorders. Find out when genetic counselling can be helpful and what to expect.

Read more on Pregnancy, Birth & Baby website

What is a congenital disorder?

Congenital disorder, also known as congenital disease or birth defects, are conditions present from birth. Find out more about congenital disorders.

Read more on Pregnancy, Birth & Baby website

Trisomy disorders - Better Health Channel

Children affected by trisomy usually have a range of birth defects, including delayed development and intellectual disabilities.

Read more on Better Health Channel website

Genomics resources for consumers | NHMRC

The Human Genome This resource provides information about the human genome and how diseases or conditions can be caused by genetic mutations. The human genome consists of the complete set of human genetic material that is contained in a human cell. In most human cells, the genetic material is made up of long DNA strands that are packaged into 23 pairs of chromosomes. A genetic disease or condition is caused by one or more genetic changes to the DNA code.

Read more on NHMRC – National Health and Medical Research Council website

Genomics explainer: types of genetic variants | Garvan Institute of Medical Research

Read more on Garvan Institute of Medical Research website

Genetic testing | Cancer Council

If you have a strong history of cancer in the family, genetic testing can be used to determine if you have the faulty gene. Find out more here

Read more on Cancer Council Australia website

Whole Genome or Whole Exome Testing for Childhood Syndromes | Pathology Tests Explained

Whole genome testing looks at DNA, reading the entire genetic code of a patient to try and determine if there are variants in genes which could be responsibl

Read more on Pathology Tests Explained website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Queensland Government logo Government of South Australia, health department logo Tasmanian government logo Victorian government logo Government of Western Australia, health department logo

Healthdirect Australia acknowledges the Traditional Owners of Country throughout Australia and their continuing connection to land, sea and community. We pay our respects to the Traditional Owners and to Elders both past and present.