GALT rs111033624: Understanding the Duarte Variant
The rs111033624 variant is a genetic change in the GALT gene, commonly referred to as the Duarte-2 (D2) allele. It is associated with a partial reduction in the activity of the galactose-1-phosphate uridylyltransferase enzyme, which is involved in processing the sugar galactose.
What each genotype means
Typical enzyme activity
You carry two copies of the common reference allele at this position in the GALT gene. This genotype is associated with normal baseline galactose-1-phosphate uridylyltransferase activity and does not indicate carrier status for the Duarte 2 (D2) hypomorphic allele. In the absence of other pathogenic mutations, this result confers standard galactose processing.
Carried by approximately 85% to 90% of individuals of European descent and over 95% of individuals of East Asian or African ancestry.
Duarte 2 carrier
You have one copy of the Duarte 2 (D2) variant, which typically yields around 75% of baseline GALT enzyme function on its own. While single carriers usually do not experience metabolic symptoms, research notes potential clinical relevance if combined in trans with a classical galactosemia mutation (forming compound heterozygous Duarte galactosemia). The evidence connecting isolated heterozygous status to diminished ovarian reserve remains limited and inconclusive.
Carried by roughly 10% to 14% of people of European ancestry, but present in less than 3% of East Asian populations.
Duarte 2 homozygote
You carry two copies of the Duarte 2 (D2) variant, which typically reduces overall GALT enzyme activity to approximately 50% of reference levels. Homozygous Duarte individuals generally process galactose adequately without developing classic galactosemia symptoms, though reproductive and carrier panels sometimes monitor this genotype. Current scientific evidence regarding long-term impacts on ovarian function or fertility is limited, with studies largely showing no clear adverse clinical outcome.
Found in less than 1% of individuals across most global populations, occurring most frequently in populations of European descent.
What is the rs111033624 Variant?
The rs111033624 variant is a specific genetic marker located within the GALT gene on chromosome 9. In the scientific literature, this variant is frequently discussed in the context of the Duarte-2 (D2) allele, which is characterized by the p.N314D amino acid substitution. This variant is often included in reproductive carrier screening panels because of its potential to interact with other GALT variants. While classic galactosemia is a serious condition caused by a near-total lack of enzyme activity, the Duarte variant is generally associated with a much milder phenotype. The variant does not eliminate the function of the GALT enzyme but rather reduces its activity to approximately 5% to 20% of normal levels. Because this variant is relatively common, it is frequently identified during routine genetic testing, leading to questions about its clinical significance for individuals and their families.
The Role of the GALT Gene
The GALT gene provides instructions for making an enzyme called galactose-1-phosphate uridylyltransferase. This enzyme is essential for the body to break down galactose, a simple sugar found in many foods, particularly dairy products. When the GALT enzyme is working correctly, it converts galactose-1-phosphate into glucose-1-phosphate, which the body can then use for energy. If the GALT enzyme is missing or significantly impaired, galactose-1-phosphate can accumulate in tissues, leading to the symptoms of galactosemia. The Duarte variant is a specific type of GALT mutation that results in a partially functional enzyme. Unlike classic galactosemia, which requires strict dietary management, individuals with the Duarte variant typically retain enough enzyme activity that they may not experience the severe health complications associated with the classic form of the disorder.
Research and Clinical Evidence
Research into the clinical impact of the Duarte variant has produced mixed findings, particularly regarding long-term health outcomes. While some early concerns suggested potential links to reproductive health, such as premature ovarian failure, subsequent studies have often failed to find a strong association between Duarte genotypes and these specific complications. Current clinical consensus generally views Duarte galactosemia as a mild or even asymptomatic condition. Because the evidence regarding developmental or long-term health risks is limited and sometimes conflicting, medical professionals often approach these results with caution. It is important to note that the presence of this variant does not constitute a diagnosis of classic galactosemia. Individuals who receive a report indicating this variant should consult with a genetic counselor or their primary healthcare provider to discuss what these findings mean in the context of their personal and family health history.
What You Can Do With This Information
Genetic information can be complex, and it is important to use it appropriately. If you have been identified as a carrier of the rs111033624 variant, the most useful step is to discuss the results with a qualified healthcare professional, such as a genetic counselor. They can help you understand the implications of your specific genotype, especially if you are planning a family, as they can explain the inheritance patterns and the likelihood of passing the variant to children. You should not use this information to make changes to your diet or medical care without professional guidance. Because the clinical significance of this variant is often debated and depends on other genetic factors, avoid drawing conclusions based solely on online databases. Always rely on personalized medical advice from a clinician who can interpret your results alongside your full clinical picture.
How common is this variant?
The rs111033624 variant is common in European populations with a minor allele frequency of approximately 0.05 to 0.07, while it is found at much lower frequencies in East Asian populations.
Frequently asked questions
Is the Duarte variant the same as classic galactosemia?
No, they are different. Classic galactosemia is caused by severe, biallelic pathogenic variants that result in a near-total lack of GALT enzyme activity, whereas the Duarte variant results in a partially functional enzyme and is generally much milder.
Do I need to change my diet if I have the Duarte variant?
You should not make any dietary changes based on this genetic information alone. Please consult with your doctor or a registered dietitian to determine if any dietary adjustments are necessary for your specific health situation.
Is the rs111033624 variant associated with ovarian health?
While some historical research investigated a potential link between GALT variants and premature ovarian failure, more recent studies have not consistently supported a strong association. The evidence remains limited and is a subject of ongoing scientific discussion.
Should I be worried if my child tests positive for this variant?
The Duarte variant is common and is often identified through newborn screening or carrier panels. It is typically considered a benign or mild finding, but you should discuss the specific results with your pediatrician or a genetic counselor to understand the implications for your child.
Sources & further reading
Educational information only, last refreshed 10/11/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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