Question to the Department of Health and Social Care:

To ask the Secretary of State for Health and Social Care, what steps his Department is taking to improve treatment of phenylketonuria.

The Government is committed to improving the lives of those living with rare diseases, such as phenylketonuria, through the UK Rare Diseases Framework.

The fourth priority of the Framework is improved access to specialist care, treatment and drugs. In February 2025, the England Rare Diseases Action Plan 2025 was published, including progress made under this priority:

- Meeting to discuss the effectiveness of early access pathways for rare disease therapies;

- Launching a review of the National Institute for Health and Care Excellence highly specialised technology programme for evaluating rare disease treatments; and

- Introducing two new actions on reforming clinical trial regulations; and developing an operational framework for individualised therapies in the National Health Service.

The NHS England Health A to Z page contains information about symptoms, medicines, tests and treatments, including what to do and when to get help. There is an NHS England webpage on phenylketonuria, which is available at the following link: https://www.nhs.uk/conditions/phenylketonuria/.

Since 2021, the treatment sapropterin has been available to all eligible people with phenylketonuria. Clinical trials suggest that around four in 10 people may benefit from sapropterin, improving their quality of life significantly and reducing restrictions on the food they can eat.