newborn screening programme

Amino acid metabolism disorders

Amino acid metabolism disorders are a group of inherited conditions. They occur because the body is missing a particular protein, or has a version which is faulty. This causes nitrogen, in the form of ammonia, and other toxic substances to accumulate in the blood. This can cause a lack of energy, poor feeding, vomiting, seizures, and damage to organs like the brain and the liver.

UK NSC screening recommendation Based on the last UK NSC review of this condition that occurred in March 2015.

Screening is not currently recommended for this condition.

Citrullinaemia (CIT) and argininosuccinate lyase (ASL) deficiency are amino acid metabolism disorders. The UK NSC does not currently recommend screening newborns for these conditions. This is because:

  • babies often show symptoms before screening test results would be available
  • tests would identify some healthy babies as having the conditions when they do not
  • there is little evidence that treating ASL deficiency early will reduce its long term effects.

Supporting documents from the 2015 review

Evidence summary Citrullinaemia & ASLD (2014)
This document provides the evidence on which the current UK NSC recommendation is based.

UK NSC coversheet & consultation responses Amino acid metabolism disorders (2015)
This document summarises the review process including the public consultation comments.

Review cycle

Date previous review completed: 2015

Next review estimated to be completed: 2021 to 2022.

To see previous evidence reviews, visit the UK NSC archive.

Organisations interested in Amino acid metabolism disorders

These organisations have expressed interest in this recommendation and may submit responses to evidence reviews.

List of organisations

If you think your organisation should be added, please contact us.