What is Galactosaemia?
Galactosemia is an inherited, lifelong metabolic disorder. The term literally means ‘ galactose in the blood ‘. People with galactosemia cannot galactose break down galactose. Galactose is a sugar which mainly comes from lactose, the sugar found in milks. Lactose is normally broken down into the two simple sugars, galactose and glucose. The galactose is then broken down further and used in many parts of the body including the brain. During metabolism nutrients are absorbed into the body cells and further modified so that the body can use them. For this process enzymes are needed. In Galactosaemia one of these enzymes (galactose-1-phosphate uridyltransferase (GALT)) does not work as it should. Galactose, galactose-1-phosphate and other harmful chemicals build up and lead that can damage of organs. As a result, complaints arise sooner or later. Especially the emergence of the long term complaints makes Galactosaemia a major disease galactosemia for a patient.
Diagnosis and screening
Pregnancy and birth of a child with galactosemia usually give no indication that there is a problem. The baby is born ‘ healthy ‘ and starts breast or bottle feeding. After a few days, the baby gets ill, because galactose and galactose 1 phosphate levels rise in the baby’s blood.
Signs of liver disease including jaundice, lethargy, poor feeding, and weight loss are very common. The severity of the liver disease varies a lot. Babies can also be prone to infection at this stage, although this does not continue to be a problem. Cataracts may also be present. These symptoms are not just seen in Galactosaemia and the pediatrician looking after your baby will do a range of tests to make the diagnosis. In some European countries Galactosaemia is part of the newborn screening programm, because the symptoms of untreated GALT can occur within days after birth. It allows doctors to start the diet before some of the harmful effects happen.
The final diagnosis is made by measuring the enzyme level in your baby’s blood. If the child has been given a blood transfusion the doctor may need to take blood from both parents to make the diagnosis.
Once the galactose-free diet has been started the liver disease will disappear and the baby will start to gain weight normally. Over time the cataracts will also disappear.
The only possible treatment is a lifelong, severe lactose free diet. All foods in which lactose is are not allowed. Lactose is in milk products and manufactured products that contain milk components: • all types of milk of mammals (also breast milk) • all types of milk products such as yogurt, cottage cheese, ice cream, butter, etc. • Certain breads, meats, margarine, candy, biscuits, medicines, etc. where milk and/or milk sugar as an ingredient is used. All galactose-free dining is not possible. Almost all natural foods, such as vegetables, fruits, cereals, meat and fish contain small amounts of galactose. However, this is so little, that they do not cause damage. Therefore, these products may just be used. In this booklet are the dietary guidelines and practical knowledge and experiences together. Also, the national organisations have a lot of information and experience available.
Of course it is sometimes difficult as the choice for products is limited. Fortunately, there are all kinds of products in the supermarket of enough lactose-free variants for sale. There are sufficient good-tasting soy products that replace the milk products. Usually hitting young parents quickly familiar with the diet and will prove that the diet is good to fit is in the everyday life of the whole family. Eating out, eat at friends, trips, parties, food, treats and also on school holidays are not so obvious. Good planning, informing the environment and bring your own food are needed to resolve these problems.The dietary guidelines are based on current medical knowledge. Past years, focused diet research led to a relaxation of the diet. Continuing research in the future possible diet contribute to an even better quality of life.
Facts and misunderstandings
- There is no medication or treatment to cure Galactosaemia. That means that Galactosaemia is a chronic (lasting) disease.
- The age expectancy is normal.
- Galactosemia is a very rare disease. .Classic Galactosaemia (GALT) occurs in 1 in every 30,000 to 60,000 newborns. (this number varies a little between the countries) It occurs in people of all ethnic groups, but it is most common in people of Irish descent.
- Galactosemia cannot arise later in life. People with galactosemia are thus born and the disease is always discovered soon after birth.
- Galactosemia is not the same as a Lactose Intolerance, which is a problem in the digestive system.
- Galactosemia is also no (cow’s milk) Allergy, where there is an issue with the defence mechanism.
Genetics of galactosemia
A human being is made up of body cells. Almost every cell contains 23 chromosomes pairs. One half of the pair contains genetic material from the mother. The other half contains genetic material from the father. The genes lie on the chromosomes.
Galactosemia is caused by an abnormality in the genes. Galactosemia is an autosomal recessive genetic condition. This means that a child must inherit two copies of the non-working gene for the GALT-enzyme, one from each parent, in order to have the condition.
Autosomal means that it is transmitted on both boys and girls. Recessive means that the abnormal gene is subordinate to the normal gene. This allows a child get sick only if the foreign gene on both chromosomes present. That can only happen if both parents are carriers of an abnormal gene. In every birth from such a couple, there is a risk of 1 in 4 that the child has galactosemia. The parents of a child with an autosomal recessive condition each carry one copy of the non-working gene, but they typically do not show signs and symptoms of the condition. The abnormal gene is with them on one of the chromosomes present and is subordinate to the normal gene (recessive). Therefore, the illness in the family of father or mother not usually manifested itself earlier.
Long term complaints
Despite the diet many patients may still get complaints in the long term. Doctors are not entirely sure whether this is because of some damage which may have occurred in the womb, or whether it is because of the prodcution of a small amount of endogenous galactose in the body.
The complaints vary by person and the severity of the symptoms varies. There seems to be no clear association between how ill the baby was initially or how quickly the diagnosis was made, and the chance of developing these difficulties. It is not clear why one patient has more problems than another.
Although it is not possible to prevent the difficulties, by picking them up early one can try to minimise the effect they have on the patient’s education and social interactions. For this reason assessments will often be carried out if there are any worries.
Most seen complaints are:
Cognitive problems. Most of the people with galactosemia have problems with learning, focus and memory. Intelligence is usually lower than average. Some of the people also need additional guidance later in life, for example in the case of household chores or at work.
Language and speech problems. A lot of the patients hav language and speech problems. This may involve problems with pronunciation, word invention, language comprehension and sentence structure. Speech therapy can help to reduce language and speech problems.
Motor problems. A small part of the people with galactosemia has problems with the control of movements; There is nothing wrong with the muscles, but with the brain. The complaints are clumsiness or rigidity, bad in sports. Sometimes balance problems or tremors may be experienced. Physical therapy and/or occupational therapy may help to move easier. There may also be problems with movements which is called motor dyspraxia. This leads to slowness in completing tasks.
Hormonal problems. Galactosaemia does seem to affect the ovaries and women may be infertile or have reduced fertility. It may be that girls do not go into puberty at the right time, or having started their periods may stop having them. All girls are kept under review and if puberty doesn’t happen at the right age a hormone replacement treatment can be given. This will be done very carefully and puberty will progress at the same rate as in a girl who has gone into puberty naturally.
For the fertility problems is currently no treatment available. There are galactosaemic women though who have had babies. The baby is not affected by the mother’s galactosaemia. Having IVF using donated eggs is also a possibilty.
Reduced bone density. In many galactosemia patients – even very young children – the mass and structure of the bones is less well crafted. Calcium and vitamin supplements and regular exercise will minimise the risk.
Social problems. A part of the patients has trouble with contacts. They find it hard to make friends and maintain friendships.
Mental health problems. Some patients suffer from depressive feelings. Some people are unusually anxious, for example in the contact with others. It is not entirely clear whether these complaints are the result of Galactosemia, but mental health problems seems more often to occur in Galactosemia than in other people.
None of the problems are life-threatening and Galactosaemic patients are otherwise as healthy as any other provided they continue on their galactose free diet throughout life. In the future we hope that research will lead to better ways of preventing some or all of the long term problems in Galactosaemia.
International Clinical Guidelines
Within the researchnetwork called GalNet, a Guidelines Working Group has been formed. It is coordinated by Dr. Annet Bosch and is composed of 19 international experts from 9 countries.
Several key questions to be addressed in the guidelines have been formulated by European and USA expert clinicians, biochemists, nutritionists and representatives from patient associations.
A consensus meeting was held in October 2015, in Amsterdam (The Netherlands), with the financial support of the Galactosemia Foundation.
The Guidelines have been recently published, and can be found here.
This information was written with the input of
- Dr. Jane Collins, Great Ormond Street Hospital, London
- Dr. Annet Bosch, Emma’s Childrens Hospital, AMC, Amsterdam
- Dr. Estela Rubio, MUMC, Maastricht