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Glutaric aciduria type 1

Glutaric aciduria type 1 (GA1) is a rare but serious inherited condition. It means the body can't process certain amino acids ("building blocks" of protein), causing a harmful build-up of substances in the blood and urine.


Babies with GA1 are unable to break down the amino acids lysine, hydroxylysine and tryptophan.

Normally, these amino acids are broken down into a substance called glutaric acid, which is then converted into energy. Babies with GA1 don't have the enzyme that breaks down glutaric acid, leading to a harmfully high level of this and other substances in the body.

Diagnosing GA1

At around 5 days old, babies are now offered newborn blood spot screening to check if they have GA1. This involves pricking your baby's heel to collect drops of blood to test.

If GA1 is diagnosed, treatment can be given straight away to reduce the risk of serious complications.

With early diagnosis and the correct treatment, the majority of children with GA1 are able to live normal, healthy lives. However, treatment for GA1 must be continued for life.

Without treatment, severe and life-threatening symptoms can develop, including seizures (fits) or falling into a coma. Some children with untreated GA1 are also at risk of brain damage, which can affect muscle movement. This may lead to problems with walking, talking and swallowing.

Around 1 in 100,000 children worldwide are thought to be affected by GA1.

Symptoms of GA1

Symptoms of GA1 usually don't appear until a few months after birth, although some babies are born with a larger-than-average head (macrocephaly).

Children with GA1 may develop some floppiness or weakness in their muscles (hypotonia) during their first year and there's a risk of developing bleeding around their brain (subdural haematoma). In rarer cases, bleeding can develop around the back of the eyes (retinal haemorrhage).

Metabolic crisis

Children with GA1 may have episodes known as a metabolic crisis, sometimes early in their life. Symptoms of a metabolic crisis include:

  • poor feeding or loss of appetite
  • lack of energy
  • abnormal movements
  • vomiting
  • irritability
  • breathing difficulties

It's important to get medical help immediately if your baby develops symptoms of a metabolic crisis. Your doctor will give you advice to help recognise the signs.

In some cases, a metabolic crisis may be triggered later in childhood by an infection or illness. The hospital should provide you with emergency treatment instructions to follow if your child is ill, which helps to prevent these symptoms developing.

Treating GA1


Children diagnosed with GA1 are referred to a specialist metabolic dietitian and given a low-protein diet. This is tailored to reduce the amount of amino acids your baby receives, especially lysine and tryptophan.

High-protein foods need to be limited, including:

  • meat
  • fish
  • cheese
  • eggs
  • pulses
  • nuts


Breastfeeding and baby milk also need to be monitored and measured, as advised by your dietitian. Regular baby milk contains the amino acids that need to be restricted, so a special formula is used instead. This contains all the vitamins, minerals and other amino acids your baby needs.

People with GA1 may need to follow a restricted protein diet for the rest of their life to reduce their risk of a metabolic crisis. As your child gets older, they'll need to learn how to control their diet and stay in contact with a dietitian for advice and monitoring.


Your child will be prescribed a medication called L-carnitine, which helps to clear some of the excess glutaric acid.

L-carnitine is given as a tablet and needs to be taken regularly, as directed by your doctor.

Emergency treatment




If your baby can't keep down their emergency feeds, or develops repeated diarrhoea, you should contact the metabolic team at the hospital to let them know you're heading straight to the accident and emergency (A&E) department.




How GA1 is inherited

The genetic cause (mutation) of GA1 is passed on by the parents, who usually don’t have any symptoms of the condition.

The way this mutation is passed on is known as autosomal recessive inheritance. This means a baby needs to receive 2 copies of the mutated gene to develop the condition – 1 from their mother and 1 from their father. If the baby only receives 1 mutated gene, they’ll just be a carrier of GA1.

If you're a carrier of the affected gene and you have a baby with a partner who's also a carrier, your baby has:

  • a 25% chance of developing the condition
  • a 50% chance of being a carrier of GA1
  • a 25% chance of receiving a pair of normal genes

Although it's not possible to prevent GA1, it's important to let your midwife and doctor know if you have a family history of the condition. Any further children you have can be tested for the condition as soon as possible and given appropriate treatment.


Information about you

If you or your child has GA1, your clinical team will pass information about you/your child on to the National Congenital Anomaly and Rare Diseases Registration Service (NCARDRS).


Find out more about the register.