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Approved PGT-M and PTT conditions

Pre-implantation genetic testing for monogenic or single-gene disorders (PGT-M) can currently be used to avoid over 1,700 genetic conditions. For some of these conditions, you can also use pre-implantation tissue typing (PTT). Find out which conditions PGT-M and PTT has been approved for and what to do if you want to avoid a condition that’s not on the list.

What are PGT-M and PTT?

PGT-M, previously known as pre-implantation genetic diagnosis (PGD), is a type of embryo testing that can be used by people with serious inherited conditions in their family. Only embryos that have been tested and found to be free of the condition are placed back into the woman’s womb.

Find out more about PGT-M

PTT is a type of embryo testing which can be used in the treatment of children with life-limiting blood disorders who need an exact tissue match for their treatment. Where a close relative isn’t available, parents can choose to have another child and use PTT treatment to only select embryos that are an exact tissue match to their older sibling. It’s for this reason that PTT is sometimes referred to as ‘saviour siblings’ technology.

Find out more about PTT

Which conditions can embryos be tested for using PGT-M and PTT?

See the full list of PGT-M conditions.

PGT-M and PTT can only be used for approved conditions - see the list of approved conditions above. The list also shows conditions that are currently awaiting approval. We will usually make a decision within two to three months.

* These conditions have also been approved for use in cases involving pre-implantation tissue typing (PTT). However, unlike PGT-M, PTT requires additional approval on a case-by-case basis for specific patients.

Find out more about pre-implantation tissue typing

What if my condition doesn’t appear on the list?

PGT-M is an area of medicine that’s changing very quickly so it may be that the condition is currently going through the approval process. If not, a licensed PGT-M clinic can apply to us on your behalf to get a new condition approved for PGT-M testing. In these cases we consider a number of different factors, such as how serious the condition is, the likelihood of it being inherited and the testimony of people affected by the condition before deciding whether to approve it for PGT-M testing.

Use of PTT has to be approved by us on a case-by-case basis so you’ll need to find a licensed PGT-M clinic who will take you through the process of getting your application approved.

Search for a licensed PTG-M clinic

Can I give feedback on conditions awaiting approval?

Yes, we very much welcome comments from people with experience or knowledge of a particular condition. Please email us at pgtm@hfea.gov.uk and we’ll discuss your feedback at the Statutory Approvals Committee.

Review date: 20 May 2026