Classical Galactosaemia (C Gal)

Classical galactosaemia (also known as 'C Gal') is an inherited condition that some babies are born with.

C Gal is caused by the body not having enough of the enzyme that breaks down galactose (a sugar found in milk). It can be life-threatening for babies, or lead to liver damage or sepsis.

All babies are screened for C Gal at birth as part of heel prick screening.

How C Gal affects babies

C Gal affects how your baby's body breaks down galactose. Galactose is 1 of the 2 sugars that make up lactose in human and cow's milk.

If a baby has C Gal, high levels of galactose build up in its body. This can become toxic and can be life-threatening. It can cause:

  • liver damage
  • jaundice
  • sepsis (blood poisoning)
  • meningitis

C Gal is not an allergy to lactose or milk.

Screening for C Gal

There are 2 ways of finding out if a baby has C Gal:

  • heel prick screening
  • the Beutler test

Heel prick screening

All babies are screened for C Gal as part of heel prick screening. This happens 2 to 5 days after being born.

Read more about heal prick screening

The Beutler test

As C Gal is generally found to be more common in babies born to Irish Traveller parents, these babies are offered a special screening test. This usually happens within a day of being born. It's called the Beutler test.

Babies with a sibling who has C Gal should also have the Beutler Test within 1 day of being born. Results are normally available the next day.

Read more about the Beutler test

Feeding your baby during screening

You may be advised by the midwife not to breastfeed your baby until the test results come through. This is to keep them safe until you are sure they do not have the condition.

Instead, you will be offered a galactose-free soya milk to feed your baby while you're waiting for the results.

If your baby does not have C Gal

If your baby does not have C Gal you can stop using galactose-free soya milk immediately. Talk to your midwife if you plan on breastfeeding.

Find out more about breastfeeding

If you plan on formula feeding, you can switch to ordinary formula when you know that your baby does not have C Gal.

If your baby has C Gal

If your baby has C Gal you will need to continue using galactose-free soya milk to manage the condition. They will need to have a galactose-free diet for their whole life.

If we don't screen for C Gal

If C Gal is not found and managed it can cause: 

  • jaundice
  • brain haemorrhage
  • sepsis (blood poisoning)
  • cataracts

C Gal can cause long-term damage later in life. This can include:

  • liver damage
  • dyspraxia (motor difficulties)
  • ataxia (disorders that affect speech, balance and co-ordination)
  • reduced fertility when they are older

These complications can still happen even when C Gal is managed.

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This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 8.

Page last reviewed: 5 November 2021
Next review due: 5 November 2024