Rare Infectious Disease News

Disease Profile

Duarte Galactosemia

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable



Duarte galactosemia is a mild variant of classic galactosemia, a condition that affects how the body processes galactose (a simple sugar found in milk, dairy products, and other foods). Unlike the other forms of galactosemia, most affected infants do not develop any concerning signs or symptoms even when breastfed or on a galactose-containing formula. Some may develop jaundice, but this symptom typically resolves quickly when the baby is switched to a low-galactose formula. Duarte galactosemia is caused by changes (mutations) in the GALT gene and is inherited in an autosomal recessive manner. People with Duarte galactosemia, specifically, typically have one severe GALT gene mutation and one milder GALT gene mutation, known as the "Duarte variant." Experts disagree regarding the risks and long-term complications of Duarte galactosemia and whether or not dietary interventions are needed. As a result, there is no standard treatment for infants with the condition. Some healthcare providers recommend partial to complete dietary restriction of milk and other high galactose foods for affected infants, but others do not.[1][2][3]


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.

Learn more

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

  • DuarteGalactosemia.org is a web site created by a team of scientists, clinicians, and families working together to improve understanding and access to information about Duarte Galactosemia.

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Duarte Galactosemia. Click on the link to view a sample search on this topic.


  1. Judith L Fridovich-Keil, PhD, Michael J Gambello, MD, PhD, Rani H Singh, PhD, RD, and J Daniel Sharer, PhD. Duarte Variant Galactosemia. GeneReviews. December 2014; https://www.ncbi.nlm.nih.gov/books/NBK258640/.
  2. The Galactosemias. The Galactosemia Foundation. https://www.galactosemia.org/understanding-galactosemia/#Duarte. Accessed 2/1/2016.
  3. Frequently Asked Questions. DuarteGalactosemia.org. https://duartegalactosemia.org/FAQs.html. Accessed 2/1/2016.