HBB Gene Variant rs387906390: Understanding Beta-Thalassemia
The rs387906390 variant is a specific genetic change located within the HBB gene. It is recognized in clinical databases as a pathogenic mutation associated with the development of beta-thalassemia, a condition affecting hemoglobin production.
What each genotype means
Typical hemoglobin production
This genotype represents the common, non-pathogenic state for this specific location in the HBB gene. Individuals with this profile do not carry the specific mutation associated with the increased risk of beta-thalassemia linked to this variant.
This is the most common genotype found in the general population across all ancestries.
Beta-thalassemia carrier status
This genotype indicates you carry one copy of the variant associated with beta-thalassemia. In an autosomal recessive inheritance pattern, carriers typically do not exhibit symptoms of the condition, though they may have mild hematological changes; please discuss these results with a healthcare provider or genetic counselor to understand your specific health context.
This genotype is rare in the general population, though it is more frequently observed in specific Middle Eastern and South Asian populations.
Increased risk of beta-thalassemia
This genotype indicates you carry two copies of the variant, which is associated with beta-thalassemia. This condition can lead to reduced hemoglobin production and potential health complications such as anemia; please consult with a medical professional or hematologist to discuss clinical implications and appropriate management.
This genotype is very rare in the general population.
What is the rs387906390 Variant?
The rs387906390 variant is a specific alteration in the DNA sequence of the HBB gene. In genomics, an rsID (reference SNP cluster ID) like rs387906390 acts as a unique identifier for a particular location in the human genome. This variant is categorized as a pathogenic mutation, meaning it is known to disrupt the normal function of the gene in which it resides. Because it is located within the HBB gene, it directly impacts the instructions the body uses to build essential blood proteins. Genetic variants are essentially typos in the genetic code; while many are harmless, some, like this one, can lead to significant health implications when inherited. Researchers track these variants to better understand how specific changes in our DNA contribute to inherited blood disorders.
The Role of the HBB Gene
The HBB gene provides the essential instructions for creating a protein called beta-globin. Beta-globin is a critical component of hemoglobin, the molecule inside red blood cells that carries oxygen from the lungs to the rest of the body. Hemoglobin is composed of different subunits, and the proper balance of these subunits is vital for healthy blood function. When the HBB gene is mutated, the body may produce either no beta-globin or significantly reduced amounts of it. This deficiency leads to a condition known as beta-thalassemia. Without enough functional hemoglobin, red blood cells cannot effectively transport oxygen, which can result in anemia and other related health challenges. The severity of the condition often depends on whether one or both copies of the HBB gene are affected.
Research and Evidence Strength
The evidence linking rs387906390 to beta-thalassemia is classified as pathogenic in clinical databases. Research into this variant is grounded in clinical observations where individuals presenting with symptoms of beta-thalassemia were found to carry this specific mutation. In the context of genetic research, 'pathogenic' indicates that there is strong evidence that the variant causes the disease. However, it is important to note that the evidence strength for any single variant can be limited by the number of documented cases. Because beta-thalassemia is a complex condition with many different possible mutations in the HBB gene, scientists continue to study how this specific variant interacts with other genetic factors. Current findings are based on clinical reports and molecular studies that confirm the variant's role in disrupting normal hemoglobin synthesis.
Population Frequency
The rs387906390 variant is considered rare in the general population. Genetic databases, such as gnomAD, track the frequency of variants across diverse ancestral groups to help researchers understand their prevalence. For rare pathogenic variants like this one, the frequency is typically very low, often appearing in only a tiny fraction of the population. Because it is rare, it is not a variant that the average person would expect to carry. Its distribution is often tied to specific geographic regions where beta-thalassemia is more common, such as parts of the Mediterranean, the Middle East, and Southeast Asia. Understanding the frequency helps clinicians and researchers assess the likelihood of the variant being present in individuals who do not have a known family history of the condition.
What You Can Do With This Information
If you have received information about this variant, it is important to understand that this is not a medical diagnosis. Genetic information is complex, and the presence of a variant does not automatically dictate a specific health outcome, as other genetic and environmental factors play a role. You cannot use this information to self-diagnose or make decisions about medical treatments. If you are concerned about your genetic health or a potential risk for beta-thalassemia, the most appropriate step is to consult with a healthcare professional, such as a genetic counselor or a hematologist. They can provide context based on your personal and family medical history, explain the implications of your results, and guide you through any necessary clinical testing or management strategies. Always discuss any health-related genetic findings with a qualified clinician.
How common is this variant?
The rs387906390 variant is rare in the general population, with its occurrence typically limited to specific ancestral groups where beta-thalassemia is more prevalent.
Frequently asked questions
What is beta-thalassemia?
Beta-thalassemia is an inherited blood disorder characterized by reduced or absent production of hemoglobin, which can lead to anemia. It is caused by mutations in the HBB gene.
Is rs387906390 dangerous?
The variant is classified as pathogenic, meaning it is associated with disease. However, the clinical impact depends on whether you carry one or two copies of the variant and other genetic factors.
Should I get tested for this variant?
Genetic testing is usually recommended if you have a family history of thalassemia or if a doctor suspects a hemoglobin disorder. You should discuss the necessity of testing with a healthcare provider.
Can I change my genotype?
No, your genotype is determined at conception and cannot be changed. Genetic information is a permanent part of your biological makeup.
Sources & further reading
Educational information only, last refreshed 10/26/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This variant is a pathogenic mutation in the HBB gene associated with hemoglobinopathies such as sickle cell disease.
This variant (c.20A>T, p.Glu7Val) causes the substitution of valine for glutamic acid in the beta-globin chain, leading to sickle cell trait or disease depending on zygosity.
Pathogenic variant (p.Glu6Val, HbS-Antilles) in HBB associated with sickle cell disease-like pathology.
Pathogenic nonsense mutation (c.118C>T / p.Gln40Ter / codon 39 nonsense) causing beta-zero thalassemia and classic carrier status (beta-thalassemia minor).
This variant, known as Hb C-Harlem, involves a double mutation in the HBB gene that can lead to sickle-beta-thalassemia-like phenotypes.
A variant in the HBB gene linked to beta-thalassemia carrier status.