Uridine Diphosphate Galactose-4-epimerase (GALE) deficiency

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This disorder is caused by a problem in the GALE gene. This gene produces the instructions for Galactose-4-epimerase (GALE) which is part of a 3-enzyme pathway that breaks down Galactose. This process is needed to produce energy within the body.

If you have a problem in the GALE gene, you will not produce enough of the GALE enzyme. Therefore, UDP-galactose will not be converted into UDP-glucose. This causes a build-up of Galactose within the body.

There are three forms of GALE deficiency base on how it affects the body:

• Generalised: affects all tissues within the body
• Peripheral: affects only red and white blood cells.
• Intermediate: affects red and white blood cells and over 50% of tissue.

There is no available figure for the prevalence of those with GALE deficiency, but it is known that generalised GALE deficiency is very rare. It is also known that those of European descent have a higher prevalence than those of Japanese and African descent.

The signs and symptoms depend on which form of the deficiency that you have.

Symptoms for the generalised disorder begin from birth; when ingesting breast milk or lactose containing formula the child will develop a range of symptoms such as;

• Hypotonia (decreased muscle tone)
• Weight loss
• Jaundice
• Liver disorders
• Aminoaciduria (amino acids within the urine)

In the most severe of cases, these symptoms can be life threatening.

Peripheral/Intermediate forms of the disorder are typically asymptomatic, with the patient being unaffected by their diet.

Following dietary restrictions such as the removal of galactose/lactose from the diet is extremely important in the cases of those diagnosed with the generalised form, it can help prevent reoccurrence of many symptoms. Removal of galactose/lactose from the diets of those with intermediate GALE deficiency can help in the long term but this will be discussed with a specialist dietician individually.

Due to the limited statistics available, a life expectancy for patients with GALE deficiency cannot be accurately stated.

GALE deficiency can be picked up on by measuring the total galactose concentration within the body and by determining the activity of the GALT enzyme. Follow up tests will be performed if the results suggest GALE deficiency.

Molecular testing via sequencing of the GALE gene can also be performed to give a confirmed diagnosis.

A test performed on a leukocyte (white blood cell) cell will confirm which form on GALE deficiency the patient has.

GALE deficiency is currently not tested for within the newborn screening test in the UK, but in the US, certain states do test for it within their newborn screening procedures.

As previously mentioned, treatment for the generalised form of GALE deficiency is mainly through the removal of galactose/lactose from the diet. This restriction of the diet may continue into the end stages of childhood. A specialist dietician will talk to you about treatment plans.

For intermediate GALE deficiency, removal of galactose/lactose from the diet is suggested as treatment, to prevent any potential long-term effects. Again, a specialist dietician will speak to you about treatment options.

For peripheral GALE deficiency, no treatment is necessary.

GALE deficiency is an autosomal recessive disease, meaning that a faulty copy of the gene must be inherited from both parents, giving a 25% chance of the child being born with the disorder. There is a 50% chance that the child will be born a carrier, which means that the child will only inherit one copy of the gene and cannot develop GALE deficiency.

As it is an autosomal recessive disorder, members of your family may be carriers, or they may have the deficiency and do not know. Genetic testing can be done for the disorder and can catch the disorder early on. Identifying carriers within your family can also assist in any family planning.

Image 1: Diagram showing inheritance patterns between two carrier parents for an autosomal recessive disorder, like GALE deficiency

References are available on request. Please contact us on 0800 652 3181 or by emailing contact@metabolicsupport.org.

Please note calls to 0800 numbers are free from UK landlines and mobiles. Calls from business lines may be charged – please check with your provider.

This information about metabolic diseases is provided by Metabolic Support UK and is intended for educational purposes only. It should not be used for diagnostic or treatment purposes.

Should you require more detailed information please contact Metabolic Support UK by email (contact@metabolicsupport.org) or by telephone ( 0800 652 3181). For specific medical information regarding a disorder or individual please contact your GP or Paediatrician. Metabolic Support UK accepts no responsibility for any errors or omissions nor does Metabolic Support UK assume any liability of any kind for the content of any information contained within this summary or any use that you may make of it.