National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Galactokinase deficiency


Other Names:
GALK deficiency; Galactosemia 2; Hereditary galactokinase deficiency; GALK deficiency; Galactosemia 2; Hereditary galactokinase deficiency; Galactokinase deficiency galactosemia; GALK-D; Galactosemia type 2 See More
Categories:
This disease is grouped under:
Galactokinase deficiency (GALK), a mild type of galactosemia, is an inherited disorder that impairs the body's ability to process and produce energy from a simple sugar called galactose. If babies with GALK eat foods containing galactose, undigested sugars build up in the blood.[1] Galactose is present in many foods, including all dairy products, many baby formulas, and some fruits and vegetables.[1][2] Children with GALK who are not treated with dietary therapy develop cataracts in the eyes, but otherwise they typically do not have long-term health problems.[2] Rarely, a child with GALK will have pseudotumor cerebri, a condition which mimics the symptoms of a large brain tumor when no brain tumor is present.[3][4] This is thought to be caused by increased pressure in the brain from cerebrospinal fluid (CSF) due to elevated levels of a galactose product in the CSF.[3] The severe medical problems that occur with "classic" galactosemia (type 1), such as liver, kidney, and brain damage, typically are not present in people with GALK.[2][3]

GALK is caused by mutations in the GALK1 gene and inheritance is autosomal recessive.[2] The disorder may be suspected in babies with an abnormal newborn screening result, or in babies with cataracts. The diagnosis can be confirmed with biochemical and molecular genetic testing.[1][3] The treatment is dietary therapy, which involves taking calcium supplements and restricting galactose in the diet throughout life to prevent cataracts.[5] If cataracts develop, they usually resolve with dietary therapy.[1][3] Children with GALK should have their growth monitored, and both children and adults should consult with a dietitian and have regular eye exams.[5] 
Last updated: 10/9/2018

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Cataract
Clouding of the lens of the eye
Cloudy lens
[ more ] 		0000518
Impairment of galactose metabolism 0004915
5%-29% of people have these symptoms
Increased intracranial pressure
Rise in pressure inside skull
0002516
Percent of people who have these symptoms is not available through HPO
Autosomal recessive inheritance 0000007
Galactosuria
Increased urinary galactose level
0012023
Hypergalactosemia 0012024
Prolonged neonatal jaundice
Prolonged yellowing of skin in newborn
0006579
Showing of 7 |
Last updated: 7/1/2020

Making a diagnosis for a genetic or rare disease can often be challenging. Healthcare professionals typically look at a person’s medical history, symptoms, physical exam, and laboratory test results in order to make a diagnosis. The following resources provide information relating to diagnosis and testing for this condition. If you have questions about getting a diagnosis, you should contact a healthcare professional.

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Newborn Screening

  • An ACTion (ACT) sheet is available for this condition that describes the short-term actions a health professional should follow when an infant has a positive newborn screening result. ACT sheets were developed by experts in collaboration with the American College of Medical Genetics.
  • An Algorithm flowchart is available for this condition for determining the final diagnosis in an infant with a positive newborn screening result. Algorithms are developed by experts in collaboration with the American College of Medical Genetics.
  • Baby's First Test is the nation's newborn screening education center for families and providers. This site provides information and resources about screening at the local, state, and national levels and serves as the Clearinghouse for newborn screening information.
  • The Newborn Screening Coding and Terminology Guide has information on the standard codes used for newborn screening tests. Using these standards helps compare data across different laboratories. This resource was created by the National Library of Medicine.
  • National Newborn Screening and Global Resource Center (NNSGRC) provides information and resources in the area of newborn screening and genetics to benefit health professionals, the public health community, consumers and government officials.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

Living with a genetic or rare disease can impact the daily lives of patients and families. These resources can help families navigate various aspects of living with a rare disease.

Education Resources

  • The Genetics Education Materials for School Success (GEMSS) aims to assure that all children with genetic health conditions succeed in school-life. Their Web site offers general and condition-specific education resources to help teachers and parents better understand the needs of students who have genetic conditions.

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Galactokinase deficiency. This website is maintained by the National Library of Medicine.
  • MedlinePlus was designed by the National Library of Medicine to help you research your health questions, and it provides more information about this topic.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Galactokinase deficiency. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Galactokinase deficiency. Baby's First Test. https://www.babysfirsttest.org/newborn-screening/conditions/galactokinase-deficiency. Accessed 10/9/2018.
  2. Galactosemia. Genetics Home Reference. August, 2015; http://www.ghr.nlm.nih.gov/condition=galactosemia.
  3. Sutton VR. Galactosemia: Clinical features and diagnosis. UpToDate. Waltham, MA: UpToDate; July 18, 2018; https://www.uptodate.com/contents/galactosemia-clinical-features-and-diagnosis.
  4. Pseudotumor Cerebri Information Page. National Institute of Neurological Disorders and Stroke (NINDS). June 20, 2018; https://www.ninds.nih.gov/Disorders/All-Disorders/Pseudotumor-Cerebri-Information-Page.
  5. Sutton VR. Galactosemia: Management and outcome. UpToDate. Waltham, MA: UpToDate; March 13, 2017; https://www.uptodate.com/contents/galactosemia-management-and-outcome.