SERPINB10 rs1243064: Food and Egg Allergy Risk
The single nucleotide polymorphism rs1243064 is an intronic regulatory variant located within the SERPINB gene cluster on chromosome 18. Published genome-wide association research has linked this variant to altered susceptibility to food allergies, specifically hen's egg allergy. Carrying the risk allele is associated with a moderate increase in the statistical likelihood of developing IgE-mediated allergic sensitization to egg proteins.
What each genotype means
Typical food allergy risk
You carry two copies of the common C allele at rs1243064. In genome-wide association studies, this baseline genotype is not associated with increased odds of developing food allergies, such as hen's egg allergy. This profile reflects an average population baseline rather than a diagnosis or immunity against allergic conditions.
Carried by approximately 35% to 42% of individuals of European ancestry, and occurs at higher frequencies in East Asian and African populations.
Slightly increased food allergy risk
You carry one copy of the T risk allele at the SERPINB cluster locus rs1243064. Large genetic studies have linked this allele to a modest statistical increase in susceptibility to food allergies, particularly hen's egg allergy. Carrying this variant does not mean you have or will develop a food allergy, as environmental factors and other genes play primary roles.
Carried by roughly 45% to 50% of individuals of European ancestry.
Increased food allergy susceptibility
You carry two copies of the T risk allele at rs1243064 within the SERPINB gene cluster. Research demonstrates that homozygous carriers have the highest relative odds of food allergy susceptibility at this locus, especially for hen's egg allergy. This finding represents a modest statistical tendency in population studies and is not a medical diagnosis of food allergy.
Carried by approximately 12% to 18% of individuals of European ancestry, but is substantially less frequent in East Asian populations.
Genomic Location and Variant Characteristics
The genetic variant rs1243064 is a single nucleotide polymorphism mapped to chromosome 18q21.33. It resides within the genomic locus encompassing the SERPINB gene cluster, specifically situated in an intronic non-coding region of the SERPINB10 gene. Because rs1243064 sits in a regulatory region rather than within an exon, it does not alter an amino acid sequence in the final protein. Instead, bioinformatic and expression quantitative trait locus (eQTL) studies suggest it acts as a regulatory variant that may modulate chromatin accessibility, transcription factor binding, or mRNA expression levels of neighboring serpin clade B genes.
Biological Role of SERPINB10 and Clade B Serpins
SERPINB10 encodes serpin family B member 10, a member of the ov-serpin subfamily of intracellular serine protease inhibitors. Unlike extracellular serpins that circulate in the bloodstream to manage systemic coagulation, clade B serpins primarily operate inside cells and mucosal epithelial barriers. They regulate endogenous proteases, suppress unwanted proteolytic cascades, and limit tissue damage during inflammation. In respiratory and epithelial tissues, SERPINB10 expression has been implicated in Type 2 helper T cell (Th2) allergic inflammation and eosinophil recruitment. Proper serpin regulation is essential for maintaining barrier integrity against external dietary and environmental antigens.
Evidence for Association with Food Allergy
Evidence linking rs1243064 to allergic disease stems primarily from large-scale discovery and replication studies of oral challenge-proven food allergies. In a prominent genome-wide association study, rs1243064 was identified as an independent risk signal in the SERPINB cluster, demonstrating genome-wide significance for hen's egg allergy (odds ratio ~1.47, p = 4.2 × 10⁻⁸) alongside broader food allergy signals. The variant showed moderate linkage disequilibrium with other regional markers, indicating independent haplotypic risk. While this provides moderate-to-strong statistical evidence for an association with hen's egg allergy in European cohorts, validation across diverse ancestral populations remains limited.
Population Distribution and Ancestry Context
The frequency of the rs1243064 variant varies considerably across global populations. In individuals of European ancestry, the minor allele frequency (MAF) typically ranges between 35% and 42%, making both heterozygous and homozygous variant genotypes relatively common. Frequencies in other geographic populations, such as East Asian, African, and South Asian cohorts, show divergent baselines according to reference databases like gnomAD and 1000 Genomes. Because the initial discovery cohorts for food allergy were predominantly of European descent, the predictive strength and effect sizes of this variant in other global ancestries are not yet fully established.
Interpreting Genetic Predisposition in Context
It is critical to interpret rs1243064 within the multifactorial nature of atopic disease. Carrying one or two risk alleles is not diagnostic of a food allergy; it merely represents a slight statistical variation in baseline liability. The development of allergic disease requires complex interactions among dozens of genetic loci—including HLA regions and epithelial genes like FLG—as well as environmental factors such as dietary introduction timing, skin barrier health, and microbiome composition. This genetic result cannot replace clinical evaluation, skin prick testing, or formal oral food challenges supervised by an allergist.
How common is this variant?
The minor allele frequency for rs1243064 ranges between approximately 35% and 42% in populations of European ancestry, with varying distributions across other global ancestral groups.
Frequently asked questions
Does having the rs1243064 risk allele mean I will definitely have an egg allergy?
No. The variant confers only a modest statistical predisposition and is not deterministic. Many people who carry the risk genotype consume eggs without any adverse immune reaction.
Can rs1243064 test results replace an allergy test?
No. Genetic variants reflect lifetime baseline risk, not active clinical status. Diagnosing a food allergy requires medical history, serum specific IgE or skin prick tests, and often supervised oral food challenges conducted by a physician.
Why is the SERPINB gene family linked to food allergies?
Genes in the SERPINB cluster produce protease inhibitors that maintain epithelial barrier health and regulate inflammatory pathways. Differences in their regulation may alter how the mucosal immune system encounters and tolerates dietary proteins.
Should I eliminate eggs from my child's diet if they have the risk genotype?
No. Dietary restrictions should never be implemented solely based on genetic testing. In fact, current pediatric guidance emphasizes safe, age-appropriate dietary introduction of potential allergens, and changes should only be made in consultation with a pediatrician or allergist.
Sources & further reading
Educational information only, last refreshed 9/11/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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