Rare disorders

A rare disorder is a health condition that affects very few people. However, about 300,000 New Zealanders have a rare disorder.

Key points about rare disorders

  1. While the exact cause of many rare disorders is not known, most rare disorders are genetic.
  2. Each disorder has a different set of signs and symptoms, and no two people experience the same rare disorder in the same way.
  3. It is often not easy to find an underlying diagnosis for a rare disorder. You may spend years consulting with different specialists and having medical tests.
  4. Many rare disorders are life-long and debilitating, and some can lead to death at a very young age.
  5. People who have a rare disorder can find support from genetic services, disability services, and disability and rare disorder support groups.

What is a rare disorder?

In Aotearoa New Zealand there is no official definition for how rare a condition must be (ie, how few people it can affect) to count as a rare disorder. Advocacy organisation Rare Disorders NZ follows the European Union policy that defines rare disorders as conditions that affect less than 1 in 2,000 people.

While these numbers seem small, there are 7,000 known rare disorders affecting up to 400 million people worldwide. In Aotearoa New Zealand, 6% of people (about 300,000) have a rare disorder. About half of the people affected by rare disorders are children.

What are the causes of a rare disorder?

The exact cause of many rare disorders is not known. But most rare disorders are genetic, which means the cause can be traced back to mutations (changes) in one of your genes. In some cases, these genetic changes are passed from one generation to the next. This explains why certain rare disorders run in families.

Genetic disorders can be present throughout your life, even if symptoms do not appear right away.

Environmental factors like the food you eat, whether you smoke or your exposure to chemicals can also play a role in rare disorders. They may directly cause your rare disorder, or they may interact with genetic factors to cause your disorder or make your disorder’s symptoms more severe.

What are the symptoms of a rare disorder?

Rare disorders can affect any part of your body and can cause a wide range of signs and symptoms. Each disorder has a different set of signs and symptoms, and no two people experience the same rare disorder in the same way. Your symptoms and your experiences living with a rare disorder may be different from someone else’s.

How is a rare disorder diagnosed?

First visit your GP. Your GP will ask you about your symptoms and health history, give you an exam and may ask questions about the health of other people in your immediate family/whānau. Your GP can also order medical tests to help find out what is causing your symptoms. This may include blood tests, x-rays, MRIs, heart tests or other procedures.

Your doctor may also refer you to one or more specialists to help diagnose your disorder and manage your ongoing care.

Trying to find an underlying diagnosis for a rare disorder can be a very long and frustrating experience. You may spend years consulting with different specialists and having medical tests. Sometimes, even after the tests and specialist visits, you may be given the wrong diagnosis or no diagnosis at all.

This can be very difficult for you your and family/whānau. Unfortunately, because there are so few cases of specific rare disorders, there is often not a doctor who has seen many (or any) similar cases. There may also be very few expert centres available for diagnosis, management and research related to your rare disorder. For this reason, it may take a doctor a long time to match your symptoms to a possible diagnosis.

GPs and specialist doctors also often don’t have the time, resources or information to properly diagnose and manage people with rare disorders, compared to more common ones.

How is a rare disorder treated?

There may not be a medicine available to specifically treat your rare disorder. Your GP and specialists will develop a treatment plan to address and manage your symptoms. It may include medicines and supportive therapies.

What is the outlook for someone with a rare disorder?

The outlook depends on the kind of disorder you have, how seriously it is affecting you and how well your disorder can be managed with medicines and other treatments. Many rare disorders are life-long and debilitating and some may lead to death at a very young age. This has impacts on you and your wider family and whānau.

Having a rare disorder may affect your emotional and mental wellbeing. Depression, stress and anxiety are common among people with rare disorders. This is because it can be difficult to cope with some of the experiences associated with a rare disorder, such as:

  • your physical symptoms
  • your disability status
  • being misdiagnosed, undiagnosed, or in the long process of trying to be diagnosed
  • challenges in accessing healthcare treatments or services.

You may also need to take time away from work or school to manage your disorder or may find your workplace or school doesn’t make appropriate accommodations. This can impact your and your family/whānau’s financial wellbeing.

How can I care for myself with a rare disorder?

Living with a rare disorder can be challenging. You may feel overwhelmed and confused, or find that you are struggling to manage your symptoms, medicines and treatments day to day.

Self-care, also known as self-management, can empower you to live well while having a rare disorder. Our self-care resources can help you learn how to manage your disorder, partner with your healthcare team to share in decisions about your treatment and take charge of the things you can change.

What support is available to people living with a rare disorder?

The support available includes:

  • genetic health services and counselling
  • disability services
  • support groups and networks.

Genetic health services and counselling

Your doctor or specialist may refer you to Genetic Health Service NZ to diagnose a condition, confirm or explain a diagnosis, discuss a family history of a genetic condition or cancer, discuss tests for a genetic condition or discuss risks and options related to prenatal and pre-implantation diagnosis. Services are publicly funded if you are a New Zealand resident.

Disability services

Many rare disorders are disabling. There are a range of funded and non-funded services available to support people living with disabilities and their families/whānau.

  • The Ministry of Health's Disability Services provides information on the range of Ministry-funded support services that are available and how you can access them.
  • Disability Information Advisory Services provide independent information and advice to disabled people, their families, whānau, aiga, caregivers and providers and the general public. The service can tell you about Ministry-funded and non-Ministry funded disability support services, and how you can find them. The service is available to everyone, for free.
  • Firstport is a New Zealand disability gateway for information, services and support.
  • The Federation of Disability Information Centres Disability-Line provides disability information and advice. Freephone 0800 693 342.

Support groups and networks

Support groups and networks can help you connect with other people who understand what it is like to live with your rare disorder. You may also be able to learn more about treatment options and the latest research related to your rare disorder.

Learn more

The following links provide further information about rare disorders. Be aware that websites from other countries may have information that differs from New Zealand recommendations.

About rare disorders

What is a rare disorder? Rare Disorders NZ
FAQs about rare diseases NIH Genetic and Rare Diseases Information Center, US
Information for patients Genetic Health Service New Zealand, NZ
Rare disorders Ministry of Health, NZ
What is a rare disease?, Rare Disease UK

Rare disorder databases

Orphanet is a portal of information on rare diseases and orphan drugs. It provides information on any disease that occurs less often than 1 in 2,000 in the population, whether genetic, autoimmune, infectious, a cancer or a disease with no accurate diagnosis.
NORD is an American organisation that helps with rare diseases and assists the organisations that serve them. The site provides general information, information on developmental drugs and a database of medical reports on more than 1,200 rare diseases. The reports include links to support organisations.
Global Genes’ RARE List provides information about a wide range of rare diseases, including links to support organisations, related news, events and clinical trials.
The Genetic and Rare Diseases Information Center (US) provides easy-to-understand information about rare or genetic disorders in English and Spanish.


  1. About rare diseases Orphanet, France
  2. Becoming an empowered patient – a toolkit for the undiagnosed RARE Toolkits, Global Genes, US, 2015
  3. Rare diseases FAQ NIH National Human Genome Research Institute, US
  4. Illuminating the rare reality Rare Disease UK, 2019
  5. Impact of living with a rare disorder in NZ Rare Disorders NZ, 2019
  6. Rare facts Global Genes, US
  7. What causes rare diseases? Rare Diseases Clinical Research Network, US
  8. What is a rare disease? EURODIS, France

Patient resources

A guide for carers Ministry of Social Development, NZ, 2016
Becoming an empowered patient – a toolkit for the undiagnosed RARE Toolkits, Global Genes, US, 2015
Disability support guide – an overview of the disability support services structure in New Zealand Disability Connect, NZ, 2016 Available in English, Korean, Arabic and Simplified Chinese 
Genetics concepts for rare disease patients and families RARE University, Global Genes, US
How to discuss genetic disease with your loved ones RARE Toolkits, Global Genes, US, 2015
Impact of living with a rare disorder in NZ Rare Disorders NZ, 2019
Talking to your family about a genetic diagnosis or test result – some tips that may help New South Wales Centre for Genetics Education, Australia, 2016
Your guide to disability support services Le Va, New Zealand, 2014 Available in English, Samoan, Cook Islands, Tongan, Fijian, Niuean and Tokelauan languages, as well as New Zealand Sign Language.

Credits: Health Navigator Editorial Team.