Genetic Testing & Counselling

Genetic testing is important as it can help us identify the specific gene mutation that is responsible for an inherited retinal condition. Because many retinal conditions share similar symptoms, a genetic diagnosis can offer clearer insight into the exact condition, how it may progress, and what it may mean for family members.

More than 300 gene mutations are currently known to cause retinal degeneration. However, not all disease-causing genes have been identified. This means that a genetic test does not always provide a definite result. Even so, testing can still play an important role in understanding vision loss, ruling out specific gene mutations, and planning future care.

Genetic testing should always be considered alongside a confirmed clinical diagnosis and appropriate genetic counselling.

A genetic result may help in the following ways:

• Identifying the specific retinal condition and guiding its management
• Explaining how the condition is inherited and who else in the family may be at risk
• Supporting informed family planning and reproductive decisions
• Identifying individuals who may be eligible for clinical trials or emerging treatments

There are many ways that genetic testing can support individuals and their families. Click on each heading to learn more.

Inherited retinal conditions can be passed down through families in different ways. The three most common inheritance patterns are explained below.

Autosomal Recessive Inheritance Pattern

Both parents carry one copy of a gene mutation but don’t usually have symptoms themselves. A child must inherit two faulty copies of the gene (one from each parent) to be affected.

With autosomal recessive inheritance, each pregnancy carries a 25% chance that the child will be affected, a 50% chance that the child will be an unaffected carrier, and a 25% chance that the child will inherit no faulty copies of the gene.

Autosomal Dominant Inheritance Pattern

Only one parent carries the gene mutation. Each child has a 50% chance of inheriting the condition, regardless of sex.

X-Linked Inheritance Pattern

The gene mutation is carried on the X chromosome. Males are more commonly affected because they have only one X chromosome. Females who carry a copy of a mutation on one of their X chromosomes may have mild symptoms

Genetic counselling is a required and important part of the genetic testing process. Genetic counsellors are specially trained healthcare professionals who support individuals and families before and after testing.

Genetic counselling helps you understand:

• What genetic testing can and cannot tell you
• The possible outcomes of a test
• The emotional impact and family implications of your results
• Issues of consent, privacy, and confidentiality

Counselling takes place before testing and again when the results are delivered, ensuring that individuals are fully informed and supported at every stage. Genetic results are always delivered personally and confidentially by a qualified genetic counsellor.

Genetic testing is carried out by specialised genetic testing laboratories. Retina South Africa can advise whether testing is best accessed through the private sector or the state healthcare system.

Genetic counselling is required before any genetic test is performed. This is a global ethical requirement followed by all accredited genetic testing laboratories.

Testing usually involves a blood or saliva sample and is analysed using advanced Next Generation Sequencing (NGS) panels. A genetic counsellor will advise on the most appropriate testing approach and the best laboratory for your needs.

Retina South Africa supports access to genetic testing through both private and state healthcare pathways.

Retina South Africa can help connect individuals with registered genetic counsellors, either locally or via virtual consultation. Genetic counselling fees are often reimbursed by medical aids, although the cost of genetic testing itself is generally not covered.

Results are delivered by the genetic counsellor and, with consent, may be shared with Retina South Africa to support research participation and clinical trial eligibility.

Some state hospitals offer limited genetic services. Retina South Africa may provide sponsorship for genetic testing in selected cases, particularly for younger patients from low-income families.

Eligibility is assessed based on factors such as age, diagnosis, family circumstances, and relevance to current or future clinical trials. Where approved, saliva kits are issued and analysed through approved South African laboratories. Timelines may vary depending on available funding.

Genetic results are delivered personally and confidentially by a qualified genetic counsellor. Results are shared only with your consent.

Retina South Africa can support individuals and families in understanding the implications of a result and, with permission, include eligible individuals in research and clinical trial databases.

Individuals may also choose to register with international research platforms such as My Retina Tracker [External Link], which allows researchers to identify potential participants for global clinical trials. Privacy and confidentiality are strictly protected.

Click on the frequently asked questions below to learn more.