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Content is anchored to trusted sources where available, but Compass has not yet been clinically reviewed. It provides general information rather than medical advice.

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Genetics and inheritance

Predictive testing

Testing a relative who has no symptoms, to see whether they carry a genetic change found in the family.

What it means

Only possible where a specific change has already been identified in an affected relative. It is offered through a structured process with counselling before and after, because the result cannot be given back and it affects far more than health.

Why you might hear it

  • Adult children often ask about it soon after a genetic result.
  • Services usually build in time to think rather than testing straight away.

What it is not

Not the same as diagnostic testing, which is done in someone who already has symptoms.

People who may help

Where Compass goes into this

About this explanation

These are plain explanations of words you may come across, not advice about your own situation. Where a word matters to a decision, the question pages go into it properly, and your own team is the place to take it.