What you carry at this position in your DNA and what research says about it.
Infection and Asthma Risk: 9/10 evidence, 12 publications.
You're viewing every possible genotype for this variant.
None of these is your result. Use the genotype toggle to compare them, then sign up and upload your DNA to see which one is yours.
Sample genotype (not yours): A/A
Lower Risk of Infection and Asthma
Two copies of the protective serine-encoding allele are present. This configuration is associated with a reduced susceptibility to leprosy and asthma.
What this genotype means: Lower susceptibility to leprosy; Reduced risk of asthma; Altered macrophage pathogen clearance.
Sample genotype (not yours): A/G
One copy of the protective serine-encoding allele is present. This configuration is associated with a reduced susceptibility to leprosy and asthma.
Sample genotype (not yours): G/G
Typical Risk of Infection and Asthma
Two copies of the common glycine-encoding allele are present. This configuration is associated with standard baseline susceptibility to leprosy and asthma.
What this genotype means: Typical baseline susceptibility to leprosy; Standard baseline risk of asthma; Typical macrophage pathogen clearance.
Gene function and biological role
Gene Function: The MRC1 gene encodes the mannose receptor, also known as CD206, which is primarily expressed on the surface of macrophages and dendritic cells [1]. This receptor plays a critical role in the innate immune system by recognizing complex carbohydrate structures on the surface of pathogens [2]. By binding high-mannose molecules on viruses, bacteria, and fungi, the receptor facilitates their engulfment and destruction [1]. Beyond pathogen clearance, the mannose receptor is involved in maintaining tissue homeostasis and regulating allergic airway inflammation [2].
Variant Impact: The rs1926736 variant is a missense change in exon 7 of the MRC1 gene that alters the encoded protein sequence [1]. This genetic variation results in a substitution of the amino acid glycine with serine at position 396 [1]. The structural change directly influences how the mannose receptor interacts with foreign pathogens and environmental allergens [2]. Research indicates that the serine-encoding version of the receptor alters immune signaling and pathogen recognition [1] [2].
Key Insight: A single amino acid change in the mannose receptor can simultaneously lower the risk of both chronic bacterial infections and allergic airway diseases.
Location: MRC1. Chromosome 10 · 10p12.33 · 17.9 Mb
Estimated prevalence by population
No frequency data available
This variant is not present in the gnomAD database.
Showing effects for A/A genotype
Immunity & Inflammation
Infection Susceptibility & Resistance
Leprosy Susceptibility. Evidence: 3/10. Source: PMID 22392581. Lower Risk.
Inflammatory & Circulating Protein Markers
Neurofascin Levels. Evidence: 6/10. Source: PMID 34648354. Lower Levels.
Organ Systems
Respiratory Health
Asthma. Evidence: 3/10. Source: PMID 19902202. Lower Risk.
Liver Function & Disease
Fatty Liver Disease. Evidence: 6/10. Source: PMID 35047847. Typical Risk.
Nutrition & Metabolism
Blood Chemistry & Metabolites
Total Protein Levels. Evidence: 9/10. Source: PMID 39789286. Lower Levels.
Blood Albumin Levels. Evidence: 8/10. Source: PMID 34594039. Typical Levels.
Showing effects for A/G genotype
Neurofascin Levels. Evidence: 6/10. Source: PMID 34648354. Typical Levels.
Total Protein Levels. Evidence: 9/10. Source: PMID 39789286. Typical Levels.
Showing effects for G/G genotype
Leprosy Susceptibility. Evidence: 3/10. Source: PMID 22392581. Typical Risk.
Neurofascin Levels. Evidence: 6/10. Source: PMID 34648354. Higher Levels.
Asthma. Evidence: 3/10. Source: PMID 19902202. Typical Risk.
Total Protein Levels. Evidence: 9/10. Source: PMID 39789286. Higher Levels.
What this genotype means for the people who carry it
Sample genotype: AA (Homozygous)
Possessing two copies of the protective serine-encoding allele significantly influences immune system behavior. Clinical studies in Vietnamese and Brazilian populations have demonstrated that this specific genetic profile offers robust protection against leprosy per se and its severe multibacillary form [1]. The structural alteration in the mannose receptor is thought to optimize the clearance of Mycobacterium leprae by macrophages [1]. Additionally, independent research in Japanese and African-American cohorts has linked this genotype to a lower risk of developing asthma [2]. The altered receptor may help modulate the inflammatory cascade triggered by common environmental allergens [2]. This dual protective effect highlights how a single molecular change can defend against both infectious pathogens and allergic airway hypersensitivity.
Lower susceptibility to leprosy; Reduced risk of asthma; Altered macrophage pathogen clearance.
Sample genotype: AG (Heterozygous)
Possessing one copy of the protective serine-encoding allele and one copy of the typical glycine-encoding allele provides a protective immune advantage. Under a dominant genetic model, having at least one serine-encoding allele is associated with a significantly lower risk of contracting leprosy [1]. This protective effect extends to multibacillary leprosy, which is characterized by high bacterial loads and widespread lesions [1]. Furthermore, genetic studies have shown that this heterozygous profile is linked to a decreased risk of asthma in diverse populations [2]. The presence of the serine variant is believed to alter how macrophages process inhaled allergens, thereby dampening the hyper-reactive airway responses that characterize asthma [2]. This balanced genetic profile helps maintain a more resilient respiratory and immune defense system.
Sample genotype: GG (Homozygous)
Inheriting two copies of the common glycine-encoding allele represents the standard baseline genetic profile found in the majority of the global population. This genotype does not carry the protective serine variant that has been shown to lower the risk of leprosy in clinical cohorts [1]. Consequently, there is a typical, baseline susceptibility to Mycobacterium leprae infection and its clinical manifestations [1]. Similarly, this genetic configuration is associated with standard baseline risks for developing asthma and allergic airway inflammation [2]. Because the glycine-encoding receptor represents the typical evolutionary baseline, it performs standard immune surveillance and pathogen clearance functions [1] [2]. Maintaining a healthy lifestyle and avoiding known environmental triggers remain the most effective ways to support respiratory and immune health.
Typical baseline susceptibility to leprosy; Standard baseline risk of asthma; Typical macrophage pathogen clearance.
Variants with shared genetic architecture
rs56278466 · MRC1 Gene · Chr 10 · Liver Enzyme Clearance
rs5743618 · TLR1 Gene · Chr 4 · Asthma and Allergy Risk
rs4833095 · TLR1 Gene · Chr 4 · Immune Response and Allergies
Content updated August 2026.
ReadYourDNA provides educational interpretation of DNA data you already have. It is not diagnostic, not a substitute for professional medical advice, diagnosis, or treatment, and is not intended to diagnose, treat, cure, or prevent any disease. Talk to a clinician before acting on any result.
Raw DNA Data Reports for 23andMe & AncestryDNA · About ReadYourDNA · FAQ · Methodology & Science · Pricing · Support and complaints · Legal & Contact · Health Traits · Pharmacogenomics · Carrier Status · Variant Explorer · The Human Karyotype · Privacy Policy · Terms of Service · Accessibility · Consumer Health Data Privacy · Your Privacy Choices · Editorial Standards · Your Data, Checkable · Sample Report · ReadYourDNA and Promethease compared · What is inside a 23andMe raw data file · What is inside an AncestryDNA raw data file · What a chatbot can and cannot do with your raw DNA file · Where a raw DNA file can still be uploaded in 2026
Written, maintained and operated by Martin Pechhacker, sole proprietor, Vienna, Austria. Trade register GISA 40064420. support@readyourdna.com