Guidance

Hereditary tyrosinaemia type 1 (HT1): summary

Published 29 September 2025

Applies to England

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In this information, the word ‘we’ refers to the NHS service that provides screening.

This information is for parents if their baby is suspected of having HT1 or has been diagnosed with HT1 following their newborn blood spot screening test (‘heel prick test’). It will help you and your healthcare professionals to talk through the next stages of your baby’s care.

1. About Hereditary tyrosinaemia type 1 (HT1)

Hereditary tyrosinaemia (pronounced tie-roh-sin-ee-me-uh) type 1 (HT1), is a rare but treatable inherited metabolic disorder that prevents the normal breakdown of protein. Babies with the condition inherit 2 faulty copies of the gene for HT1, one from each parent.

Untreated HT1 can cause long-term health problems, including liver and kidney damage. Newborn screening allows an early diagnosis and treatment which can improve the long-term outcome.  

2. Screening and diagnosis of HT1

2.1 Newborn blood spot

When your baby was about 5 days old, your midwife took some blood from your baby’s heel for their newborn blood spot screening test. The test measures the amount of a substance called succinylacetone (SUAC) in your baby’s blood. A high level of SUAC suggests your baby may have HT1. This is called a condition suspected or screen positive result.

2.2 Diagnostic tests

If your baby has a screen positive result, you will be seen by a metabolic doctor, dietitian and nurse specialist (the ‘metabolic team’). The team will provide advice and support. Blood and urine tests will be carried out to confirm if your baby has HT1 and a sample will be taken for genetic testing.

You will need to wait a few days for the test results. However, if required, treatment will start immediately based on the screening test results and initial diagnostic test results, as HT1 can be life-threatening if left untreated.

Some babies may already be unwell and on treatment before the screening test results are reported.

2.3 Treatment

If your baby does have HT1, the metabolic team will explain the condition in more detail and answer any questions you might have. They will start your baby on medical treatment and a special feed plan. They will also arrange regular follow-up appointments. Following the feed plan and treatment instructions is very important for your baby’s health.

3. Confidentiality

The NHS screening programmes use personal information from your NHS records to invite you for screening at the right time and use your information to ensure you receive high quality care and to improve the screening programmes. Find out more about how your information is used and protected, and your options at www.gov.uk/phe/screening-data.

4. More information and support

The metabolic team will be happy to discuss any queries you might have.

Further information can be found from Metabolic Support UK at www.metabolicsupportuk.org

The Metabolic Support UK team can be contacted at:

The British Inherited Metabolic Diseases Group (BIMDG) website has a booklet about tyrosinaemia at bimdg.org.uk/education/temple

NHS.UK has information about newborn blood spot screening at www.nhs.uk/baby/newborn-screening/blood-spot-test.

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