What are the effects of galactosemia?
Normally when a person consumes a product that contains lactose, the body breaks the lactose down into galactose and glucose. Galactosemia means too much galactose builds up in the blood. This accumulation of galactose can cause serious complications such as an enlarged liver, kidney failure, cataracts in the eyes or brain damage.
What causes galactosemia in children?
This disease is caused by elevated levels of galactose (a sugar in milk) in the blood resulting from a deficiency of the liver enzyme required for its metabolism (breakdown). Galactosemia is hereditary. To have the disease, a child must inherit the tendency from both parents.
Are there any other disorders similar to galactosemia?
Related Disorders. Symptoms of the following disorders can be similar to those of galactosemia. Comparisons may be useful for a differential diagnosis: Galactokinase (GALK) deficiency is associated with cataracts, increased blood concentration of galactose and increased concentration of galactitol in the urine.
What is the prevalence of galactosemia?
Classic Galactosemia occurs in 1 in 30,000 to 60,000 newborns. Galactosemia is an inherited disorder that prevents a person from processing the sugar galactose, which is found in many foods. Galactose also exists as part of another sugar, lactose, found in all dairy products.
What causes liver damage in galactosemia?
Galactosemia is a rare hereditary disease that can lead to cirrhosis in infants, and early, devastating illness if not diagnosed quickly. This disease is caused by elevated levels of galactose (a sugar in milk) in the blood resulting from a deficiency of the liver enzyme required for its metabolism (breakdown).
What body system is affected by galactosemia?
Galactose is a simple sugar found in milk products. Glucose is the usable form of sugar in the human body. Since there is not enough of the enzyme, galactose builds up in the blood. This build up can cause severe damage to the liver, kidneys, central nervous system, and other body systems.
Why do you get jaundice with galactosemia?
Classic galactosemia results from mutations in the galactose-1-phosphate uridyl transferase gene and causes infants to present with jaundice after initiation of lactose containing formulas. Jaundice associated with galactosemia is often thought to have a prominent direct fraction.
What does galactosemia lead to?
Untreated galactosemia can lead to liver damage, kidney failure, and intellectual disabilities.
How does galactosemia affect the kidney?
Low levels of the enzyme causes the high galactose level in the blood. Galactosemia can cause serious problems. These include an enlarged liver, kidney failure, and brain damage.
What enzyme is involved in galactosemia?
Classic galactosemia occurs when an enzyme called galactose-1-phosphate uridyltransferase (GALT) is missing or not functional. This liver enzyme is responsible for breaking down galactose (a sugar byproduct of lactose found in breast milk, cow's milk and other dairy foods) into glucose.
What is bilirubin metabolism?
INTRODUCTION. Bilirubin is the catabolic product of heme metabolism. Within physiologic range, bilirubin has cytoprotective and beneficial metabolic effects, but in high levels it is potentially toxic. Fortunately, there are elaborate physiologic mechanisms for its detoxification and disposition.
What does unconjugated bilirubin do?
Some bilirubin is bound to a certain protein (albumin) in the blood. This type of bilirubin is called unconjugated, or indirect, bilirubin. In the liver, bilirubin is changed into a form that your body can get rid of. This is called conjugated bilirubin or direct bilirubin.
What are some effects of untreated galactosemia?
A. Untreated galactosemia can cause rapid, unexpected death due to an infection that invades the blood. Infants with untreated galactosemia may also develop brain damage, liver disease, and cataracts. Each child with galactosemia is different so the outcome will not be the same for all children.
Is galactosemia a metabolic disorder?
At Boston Children's Hospital, we have already helped many infants and families who have been affected by galactosemia, a rare genetic metabolic disorder in which babies are born without the ability to convert the milk sugar, galactose, into glucose (the form of sugar used by the body for energy).
What is galactosemia and discuss causes and symptoms?
Symptoms start to show up within a few days after they begin to drink breast milk or formula with lactose -- the milk sugar that contains galactose. Your baby first loses their appetite and starts vomiting. Then they get jaundice, a yellowing of the skin and the whites of their eyes. Diarrhea is common, too.
What product accumulates in the blood and tissues with Galactokinase deficiency galactosemia?
In galactokinase deficiency galactitol and galactose accumulate in tissues.
What is the life expectancy of someone with galactosemia?
With a galactose-restricted diet patients have a normal life expectancy. However, patients may still suffer long-term complications such as problems of mental development, disorders of speech, hypergonadotrophic hypogonadism and decreased bone mineral density (Bosch 2006).
How many chances are there of having a baby with galactosemia?
For each pregnancy, in such a family, there is a 1 in 4 chance a baby will be born with the deficiency. Because of the potentially disastrous effects of late diagnosis, many provinces have mandatory neonatal screening programs for galactosemia.
What are the symptoms of a baby with a swollen liver?
The disease usually appears in the first few days of life following the ingestion of breast milk or formula. Vomiting, liver enlargement, and jaundice are often the earliest signs of the disease, but bacterial infections (often severe), irritability, failure to gain weight, and diarrhea may also occur. If unrecognized in the newborn period, the disease may produce liver, brain, eye and kidney damage.
Can you do a galactose tolerance test?
Affected patients have no enzyme activity; carriers (parents) have intermediate enzyme activity (about half the normal level). A galactose tolerance test should never be done, as it may be harmful. Affected infants who ingest galactose will excrete it in large quantities in their urine where it can also be detected.
Can galactosemia be considered in infants?
With early therapy, any liver damage which occurred in the first few days of life will nearly completely heal. Galactosemia should be considered in any jaundiced infant because of beneficial effects of early dietary restriction.
How do you know if you have galactosemia?
The most common symptoms include: loss of appetite. vomiting. jaundice, which is yellowing of the skin and other parts of the body. liver enlargement. liver damage. fluid building up in the abdomen and swelling. abnormal bleeding.
What is the name of the condition where there is too much galactose in the blood?
Galactosemia means having too much galactose in the blood. The buildup of galactose can lead to serious complications and health problems. There are four main types of galactosemia disorders: type 1, or classic and clinical variant galactosemia. type 2, or galactokinase deficiency. type 3, or epimerase deficiency.
What is the genetic disorder that affects how your body metabolizes galactose?
Galactosemia is a rare genetic disorder that affects how your body metabolizes galactose. Galactose is a simple sugar found in milk, cheese, yogurt, and other dairy products. When it’s combined with glucose, it makes lactose. Galactosemia means having too much galactose in the blood.
What is the best treatment for galactosemia?
Treatment. The most common treatment for galactosemia is a low-galactose diet. This means that milk and other foods that contain lactose or galactose can’t be consumed. There is no cure for galactosemia or approved medication to replace the enzymes.
How many babies are affected by galactosemia?
Incidence. Type 1 galactosemia occurs in 1 out of every 30,000 to 60,000 babies. Type 2 galactosemia is less common than type 1 and occurs in 1 out of every 100,000 babies. Type 3 and Duarte variant galactosemia are very rare.
Can galactosemia be life threatening?
The buildup of galactose in the blood can be dangerous. Without diagnosis and intervention, galactosemia can be life-threatening in newborns.
Does galactosemia affect learning?
In addition, children who have learning disabilities and other delays may benefit from individual education plans and intervention. Galactosemia can increase the risk of infections, so control ling infections when they occur is crucial. Antibiotic treatments or other medications may be necessary.
What are the symptoms of galactosemia?
Diarrhea, irritability, lethargy and a bacterial infection may also be early signs of galactosemia. In time, wasting of body tissues, marked weakness, and extreme weight loss occur unless lactose is removed from the diet.
Where does galactosemia occur?
An increased frequency of galactosemia occurs in individuals of Irish ancestry. Clinical variant galactosemia occurs most often in African Americans and native Africans in South Africa who have a specific GALT gene mutation.
What is the name of the disorder that affects the body's ability to convert galactose to glucose
General Discussion. Galactosemia is a rare, hereditary disorder of carbohydrate metabolism that affects the body’s ability to convert galactose (a sugar contained in milk, including human mother’s milk) to glucose (a different type of sugar). The disorder is caused by a deficiency of an enzyme galactose-1-phosphate uridylyl transferase (GALT) ...
How to tell if an infant has galactosemia?
An infant with galactosemia appears normal at birth, but within a few days or weeks loses his or her appetite (anorexia) and starts vomiting excessively. Yellowing of the skin, mucous membranes, and whites of the eyes (jaundice), enlargement of the liver (hepatomegaly), appearance of amino acids and protein in the urine, growth failure, and, ultimately, accumulation of fluid in the abdominal cavity (ascites) with abdominal swelling (edema) may also occur. Diarrhea, irritability, lethargy and a bacterial infection may also be early signs of galactosemia. In time, wasting of body tissues, marked weakness, and extreme weight loss occur unless lactose is removed from the diet.
How to prevent galactosemia?
In order to avoid the consequences of galactosemia, which may include liver failure and kidney dysfunction, brain damage and/or cataracts, infants must be treated promptly by removing lactose from the diet. Children treated with this special diet usually show satisfactory general health and growth.
How many births are affected by galactosemia?
Affected Populations. Classic galactosemia is diagnosed in the range of 1/16,000 to 1/48,000 births through newborn screening programs around the world, depending on the diagnostic criteria used by the program. The disorder has been reported in all ethnic groups.
What enzyme is needed for the breakdown of milk sugar?
This leads to abnormal accumulation of galactose-related chemicals in various organs of the body causes the signs and symptoms and physical findings of galactosemia. The galactose-1-phosphate uridyl transferase (GALT) enzyme is needed for the breakdown of the milk sugar, galactose. Deficiency of this enzyme results in the accumulation ...
What are the different types of galactosemia?
There are 3 main types of galactosemia which are distinguished based on their genetic causes, signs and symptoms, and severity: [1] [3] [4] [5] [6] Classic galactosemia (type 1) - the most common and severe type, caused by mutations in the GALT gene, and characterized by a complete deficiency of an enzyme called galactose-1-phosphate uridyl ...
What is galactose in food?
Galactose is present in many foods, including all dairy products (milk and anything made from milk), many baby formulas, and some fruits and vegetables. [1] [2] The impaired ability to process galactose can be due to the deficiency of any of 3 enzymes, caused by mutations in different genes. [3] . There are 3 main types ...
Is Duarte variant galactosemia a variant of Galactosemia?
There is also a "variant" of classic galactosemia called Duarte variant galactosemia, in which a person has mutations in the GALT gene but has only partial deficiency of the enzyme.
Can low galactose cause jaundice?
Infants with this form may have jaundice, which resolves when switched to a low-galactose formula. Some studies have found that people with this form are at increased risk for mild neurodevelopmental problems, but other studies have found there is no increased risk. The risk may depend on the extent of the deficiency.
Is galactosemia autosomal recessive?
Inheritance of all types of galactosemia is autosomal recessive. [1] [3] The diagnosis may be suspected based on symptoms or results of newborn screening tests, and can be confirmed by measuring enzyme activity and genetic testing. [3] .
How to treat galactosemia in infants?
This is usually accomplished by switching the baby from drinking breast milk or a milk-based formula to drinking a low galactose formula, such as soy or elemental formula.
What is the genetic makeup of a galactose?
Patients with classic galactosemia are sometimes described as having the genetic makeup "G/G.". When a person who does not have galactosemia consumes food containing lactose (e.g., dairy products such as milk, cheese, butter), their body breaks down the lactose into galactose and glucose, and then further metabolizes both of these sugars.
What is the mutation of Duarte galactosemia?
Duarte variant galactosemia, sometimes called just Duarte galactosemia or “DG,” is much more common than classic or clinical variant galactosemia in many populations and also results from mutations in the GALT gene. However, instead of carrying severe mutations in both copies of their GALT gene, patients with Duarte variant galactosemia carry one GALT copy with a severe (G) mutation and a second GALT copy that is only very mildly impaired and that shows characteristic sequence changes that classify it as "Duarte” (also called D or D2).
What is the genetic disorder that results from compromised ability to metabolize the sugar galactose?
Galactosemia is a family of genetic disorders that result from compromised ability to metabolize the sugar galactose; the term “galactosemia” literally means too much galactose in the blood. The different types of galactosemia include. Classic and clinical variant galactosemia (aka Type 1 galactosemia)
Can galactokinase be detected in newborn?
Specifically, some newborn screening protocols are designed to detect galactokinase deficiency, while others are not. Receiving a “normal” newborn screening result for galactosemia therefore may not rule out a diagnosis of galactokinase deficiency.
Can you detect Duarte variant galactosemia?
Newborns with Duarte variant galactosemia may or may not be detected by the same newborn screening test that detects classic or clinical variant galactosemia. Specifically, some newborn screening protocols detect Duarte variant galactosemia, while others do not.
Can galactose build up in the body?
When a person with galactosemia consumes food containing lactose or galactose they are not able to fully metabolize the galactose, so it can build up in their cells and tissues. Galactose that is synthesized in the body may also build up.
Signs and symptoms
- An infant with galactosemia appears normal at birth, but within a few days or weeks loses his or her appetite (anorexia) and starts vomiting excessively. Yellowing of the skin, mucous membranes, and whites of the eyes (jaundice), enlargement of the liver (hepatomegaly), appearance of amino acids and protein in the urine, growth failure, and, ultima...
Prognosis
- Children with galactosemia who have not received early treatment may show arrested physical and mental development and are particularly susceptible to cataracts in infancy or childhood. In severe cases, overwhelming infection can cause life-threatening complications, but mild cases present few symptoms and no serious impairment(s). In order to avoid the consequences of gal…
Risks
- The above-mentioned complications associated with classic galactosemia and clinical variant galactosemia have not occurred in individuals with Duarte variant galactosemia, which is the best example of biochemical variant galactosemia subdivision. Significant debate exists in the medical literature as to whether individuals with Duarte variant galactosemia need to maintain a special …
Cause
- Galactosemia is an autosomal recessive hereditary disorder caused by a deficiency of the enzyme galactose-1- phosphate uridyl transferase (GALT) that is needed for the breakdown of the milk sugar, galactose. Deficiency of this enzyme results in the accumulation of toxic products: galactose-1-phosphate (a derivative of galactose), and galactitol (an alcohol derivative of galact…
Pathophysiology
- Galactosemia occurs due to disruptions or changes (mutations) of the GALT gene. The abnormal accumulation of galactose-related chemicals in various organs of the body causes the signs and symptoms and physical findings of galactosemia.
Epidemiology
- Classic galactosemia is diagnosed in the range of 1/16,000 to 1/48,000 births through newborn screening programs around the world, depending on the diagnostic criteria used by the program. The disorder has been reported in all ethnic groups. An increased frequency of galactosemia occurs in individuals of Irish ancestry. Clinical variant galactosemia occurs most often in Africa…
Diagnosis
- Symptoms of the following disorders can be similar to those of galactosemia. Comparisons may be useful for a differential diagnosis: Classic galactosemia and clinical variant galactosemia are diagnosed when galactose-1-phosphate is elevated in red blood cells and GALT enzyme activity is reduced. Molecular genetic testing is also available to identify mutations in the GALT gene. Near…
Clinical significance
- Galactokinase (GALK) deficiency is associated with cataracts, increased blood concentration of galactose and increased concentration of galactitol in the urine. Galactitol accumulates in the lens of the eye where it causes lens swelling and protein precipitation and, subsequently, cataracts. GALK deficiency is an autosomal recessive genetic disorder caused by mutations in t…
Overview
- Lactose intolerance (LI) is a metabolic disorder characterized by the inability to break down lactose, the predominant sugar found in milk and milk products. People with LI cannot properly digest lactose because they lack or are deficient in the intestinal enzyme lactase which is key to the digestion of lactose. Lactose is a complex sugar made up of two different sugar molecules (…
Treatment
- Treatment A lactose tolerance test should NOT be administered to galactosemic children. Fortunately the body of an infant with galactosemia can synthesize galactolipids and other essential galactose-containing compounds without the presence of galactose in food. Therefore, satisfactory physical development is possible if a strict diet is followed. Speech therapy may be …
Prevention
- Infants and children with galactosemia should reduce galactose intake and have a diet that contains lactose-free milk substitutes and other foods such as soy bean products.
Resources
- Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site. Fridovich-Keil J, Bean L, He M, Schroer R. Epimerase Deficiency Galactosemia. 2011 Jan 25 [updated 2013 Oct 24]. In: Pagon RA, Adam MP, Ardinger HH, et al., …
Literature
- Fridovich-Keil JL, Walter JH. Galactosemia. In: Valle D, Beaudet AL, Vogelstein B, Kinzler KW, Antonarakis SE, Ballabio A, Gibson K, Mitchell G, eds. The Online Metabolic and Molecular Bases of Inherited Disease (OMMBID). Chap 72. New York, NY: McGraw-Hill. 2015. Berry GT, Walter JH. Disorders of Galactose Metabolism. In: Saudubray JM, van den Berghe G, Walter JH, eds. Inborn …
Selected publications
- Hoffmann B, Dragano N, Schweitzer-Krantz S. Living situation, occupation and health-related quality of life in adult patients with classic galactosemia. J Inherit Metab Dis. 2012;35:10518. [PubMed: 22447152].