If you are affected by mitochondrial disease (mito), there may be ways to lower the risk of passing mito on to your future children. It is recommended to get advice about your reproductive health as early as possible. As women get older, their fertility can decrease, and options may become limited. Some types of mito can also impact fertility in both males and females.8

When you are thinking about having children, it is important to be aware of all the options you have. This way, you can make informed decisions. Each family has different options based on genetics, individual beliefs, and costs.

Understanding reproductive options

Your choices for having children may vary based on whether the genetic change causing mito is in nuclear DNA (nDNA) or mitochondrial DNA (mtDNA).

Some of these options include IVF. It can help healthy children be born, but it does not work for everyone. Sometimes fertility drugs don’t work, there may not be enough eggs to retrieve, and embryos might not develop or implant. Even if pregnancy occurs, there’s still a risk of miscarriage just like in any pregnancy. Read more about understanding IVF success rates, which have been written by the Victorian Assisted Reproductive Treatment Authority.

In addition, surrogacy is an option for women with health challenges or risks related to symptoms of mito. A surrogacy can be an option used in combination with other reproductive options.

Learn more about genetic testing and mito or find information to help understand your diagnosis.

 

Options for building your family info sheet

Nuclear DNA changes

The chance of a child inheriting an nDNA genetic change from their parents depends on the type of change:

  • 25% chance for autosomal recessive genetic changes.2
  • 50% chance for autosomal dominant genetic changes.3
  • The chance is varied by sex for X-linked inheritance. Male children will be more likely to be at risk of having signs and symptoms, females can be healthy carriers of the gene or show (milder) symptoms.2
  • Other forms of inheritance can also occur, including “de novo” genetic changes that are not found in either parent. These typically have a low risk (less than 5%) of being present in subsequent pregnancies.

You can find out more about your chance of having a child with mito caused by an autosomal recessive gene change through genetic carrier testing or screening. Genetic counselling can help you understand what the test involves and make sense of the results.

Reproductive genetic carrier testing  is used when families with a history of mito want to know if they are a carrier of a gene that may cause mito in their children. If you have a family history of mito, you may be able to access this testing for no cost through a public hospital genetics service.

Reproductive genetic carrier screening is used to tell future parents whether they have an increased risk of having a child with some specific genetic conditions. It's usually done before pregnancy and is a test that examines the genes of future parents. It looks for any gene changes that increase the risk of future parents having a child with a genetic condition. Some, but not all carrier screening tests include some types of mito.

Genetic carrier screening is explained in more detail here.

Access to genetic carrier testing or screening may be different in each Australian state. For more information visit genetic counselling and mito.

In Australia, reproductive genetic carrier screening is funded by Medicare for a small set of conditions. Mito is not included on this list. However, future parents can choose to have a test that does include some forms of mito by paying the difference for a more comprehensive test.

Options for nuclear DNA changes

When families know they have an increased risk of having a child with mito due to a nDNA change, they can consider options to reduce that risk.

These options include:

The best choice for your family is different for everyone and depends on your genetic changes, beliefs, preferences, and the costs of each option.

Mitochondrial DNA changes

Males who carry mtDNA genetic changes won't pass the changed gene to their children. This is because babies inherit all of the mtDNA from their mothers.

Many people with mtDNA genetic changes have a mixture of healthy and changed mitochondria, known as heteroplasmy. The proportion of mtDNA that is changed in mitochondria is called the level of heteroplasmy or the mutant load. It is usually measured as a percentage, which can vary between your different body parts. When the amount of changed mitochondria exceeds a certain level, symptoms of mito become evident, that can lead to a mito diagnosis.

The exact amount of changed mitochondria that will cause signs and symptoms of mito in anyone is not easy to predict. Researchers are collecting information to learn more about how likely it is to get signs and symptoms of mito from various genetic changes.

A mother can pass on different amounts of changed mitochondria to each child, which can cause different levels of heteroplasmy among biological siblings. Therefore, it is difficult to predict the risk of mito for any children of a mother with mtDNA heteroplasmy.1

The severity of mito in a child depends on the level of heteroplasmy. Modified from: Taylor, R. W. & Turnbull, D. M. Mitochondrial DNA mutations in human disease. Nat. Rev. Genet. 6, 389–402 (2005).

Options for mitochondrial DNA changes

If you have a mtDNA genetic change, there are options to reduce your risk of having a child with mito.

These options include:

The best choice for your family is different for everyone and depends on your genetic changes, beliefs, preferences, and the costs and availability of each option.

Understanding your options

In alphabetical order.

Summary

  • There are many reproductive options for mito. The options that are relevant to you will depend on your genetics, your beliefs and the costs and avaliabilty of each option.
  • Seek advice early if you have mito to explore ways of lowering the risk of passing it on to your children, especially considering age-related fertility changes.
  • Understand reproductive options based on whether the genetic change causing mito is in nuclear DNA or mitochondrial DNA.
  • Genetic testing and counselling play a key role.

Disclaimer: Resources provided by the Australian Mitochondrial Disease Foundation Limited (Mito Foundation), offers general information and is not a substitute for medical advice. It is essential to assess the suitability of the content for your individual circumstances and make decisions based on your medical condition. The information’s accuracy is subject to change, and we do not guarantee ongoing currency or availability. While efforts are made to ensure accuracy, Mito Foundation is not obligated to provide updated information. The copyright for this document and its content belongs to, or is licensed to, Mito Foundation, and reproduction without prior written consent is prohibited.

Author(s): Mito Foundation
Reviewer(s): David Thorburn BSc(Hons) PhD FHGSA FFSc(RCPA) FAHMS,  Suzanne Sallevelt MD PhD FRACP and members of the mito community.
Version: 2.1
Date published:  9 July 2024    

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