Epigenetic clocks explained

Epigenetic clocks explained looks at specific genes or genetic markers, usually from a blood or saliva sample, to identify inherited variants that may be relevant to your health or that of your family. It's typically requested because of a personal or family history that raises the possibility of a specific inherited condition. Results are usually discussed with genetic counselling support given the personal implications involved.

This is usually most relevant for people with a relevant family history, a personal diagnosis that suggests a genetic cause, or specific ethnic or population risk factors. A genetic counsellor or specialist can help assess whether testing is likely to be useful in your particular situation before you proceed. Testing is a personal decision, and support is available to help you weigh up the potential implications beforehand.

Most genetic tests need no physical preparation beyond providing a blood or saliva sample, but pre-test counselling is often recommended so you understand what a result could mean. This is different from most other tests, since the implications can extend to other family members as well as yourself. The clinic will explain what to expect during the consent and counselling process.

The sample collection itself is usually quick and straightforward — typically a blood draw or a saliva/cheek swab. Analysis is carried out in a specialist laboratory and takes considerably longer than a standard blood test because of the complexity involved. You'll usually have a consultation both before and after testing to discuss what's involved and what the result means.

The physical risks of sample collection are minimal, similar to a standard blood test. The more significant considerations are emotional and practical — how you might feel about a result, and potential implications for insurance, family planning or relatives. Genetic counselling before testing is designed to help you think through these issues in advance.

Genetic tests generally take longer than routine blood tests, often several weeks, because of the detailed laboratory analysis involved. Your clinician will give you an expected timeframe specific to the test being carried out. Results are usually delivered in a follow-up consultation rather than a written report alone.

A positive result means a specific genetic variant has been identified, and a specialist will explain what this means for your health risk and any recommended next steps, such as increased monitoring or preventative options. It may also have implications for blood relatives, who can be offered testing of their own if relevant. You'll be supported through this discussion rather than simply given a result on paper.

NHS genetic testing is generally available where specific clinical criteria are met, such as a strong family history, though this can involve a wait for assessment and results. Private genetic testing can offer quicker access and may be considered by people who don't meet NHS eligibility criteria but still want to understand their risk. Cost varies by provider and varies depending on the scope of the test.

Modern genetic testing is highly accurate at detecting the specific variants it's designed to look for, when carried out in an accredited laboratory. However, a negative result doesn't rule out all possible genetic contributions to a condition, and results are best interpreted with specialist input. Your genetic counsellor or specialist can explain the specific accuracy and limitations relevant to your test.

You can typically arrange an initial consultation with a private clinic or genetic specialist to discuss whether testing is appropriate for you. This usually includes pre-test counselling, the test itself, and a follow-up appointment to discuss results. Contact the clinic to ask about availability and what the process involves.