Background
Galactosaemia is a rare genetic disorder that can cause a severe life-threatening illness in babies fed with breast milk or standard formula milks. In addition some long-term problems occur in most children even with treatment.
Credits
Last updated March 2019 by Dr Elisabeth Jameson, Consultant Paediatrician, Inherited Metabolic Disease, Willink Biochemical Genetics Unit, Genetic Medicine, Manchester Academic Health Science Centre, Manchester, UK.
Although great care has been taken in the compilation and preparation of all entries to ensure accuracy, we cannot accept responsibility for any errors or omissions. Any medical information provided is for education/information purposes and is not designed to replace medical advice by a qualified medical professional.
Babies with galactosaemia become unwell in the first few days or weeks after birth. Symptoms include:
- feeding difficulties
- vomiting
- jaundice (yellowing of the skin and the whites of the eyes due to build-up of a substance called bilirubin)
- liver and kidney disease
- cataracts
- poor weight gain
If the disorder is not treated promptly there is a risk of death due to liver failure, bleeding or infection.
Older children, even with treatment, usually have some difficulties with learning and speech development. Most girls with galactosaemia have a delay in their pubertal development and as women are infertile.
Human milk and milk from other animals contains the sugar galactose. This sugar must be changed into glucose for it to be used by the body. In classical galactosaemia the GALT enzyme, that is necessary for doing this is not made correctly. Galactose and other substances increase in the body causing the illness.
In some countries (not the UK) galactosaemia is looked for in blood from the new born heel prick test. In the UK, the diagnosis is generally made by investigating babies who become unwell. The diagnosis can be made by a simple blood test of the GALT enzyme.
Breast or standard formula milk should be stopped in any baby suspected of having galactosaemia. Once this is done, the symptoms of severe liver and kidney problems usually resolve. Soya or other special milk formulas can be given as these do not contain galactose.
In children who have been weaned off milk, other products containing galactose must be excluded from the diet. These are generally dairy products such as cheese and yoghurt.
Girls with galactosaemia will usually require hormone treatment in order to proceed into puberty. This will be managed by a specialist doctor called an endocrinologist and a referral will be made once the girl reaches about 10 years of age.
Inheritance patterns
Galactosaemia is an autosomal recessive, inherited condition and so is life-long. The parents of children with galactosaemia will each have one normal and one abnormal gene that makes the GALT enzyme. One normal gene makes enough enzyme so that parents do not have the disorder themselves. However, at the time of conception there is a 1 in 4 chance or 25% chance their baby will have inherited both the abnormal genes from his/her parents. He/she is then unable to make the GALT enzyme and as a consequence has galactosaemia. If a baby is at risk he/she will be tested at birth and started on a galactose free formula while the result is awaited. Affected families should be referred to a genetics centre for advice and support.
Prenatal diagnosis
This is possible by chorionic villus sampling at ten to 12 weeks with amniocentesis at 16 weeks if necessary.
Galactosaemia Support Group
Tel: 0121 378 5143
Email: [email protected]
Website: galactosaemia.org
The Group is a Registered Charity in England and Wales No. 1020167. It provides information and support to anyone affected by galactosaemia, and puts families in contact with each other.
Group details last updated March 2019.
As galactosaemia is a metabolic disease, information and advice are also available from Metabolic Support UK (see entry Inherited Metabolic diseases).