rs6656401

Variant in the CR1 gene (Complement Receptor 1 (CD35))

rs6656401 is a single nucleotide polymorphism (SNP) in the CR1 gene, involved in complement receptor / immune complex clearance. Variants at this position have been studied in relation to immune function, metabolism, and chronic illness.

This page is for educational and informational purposes only. Not a diagnostic tool. Always consult a qualified healthcare provider.

What is the rs6656401 variant?

rs6656401 is a SNP (single nucleotide polymorphism) in the CR1 (Complement Receptor 1 (CD35)) gene. It belongs to the Immune Signaling category and is part of the Immune System & Inflammation biological cluster. CR1 encodes complement receptor 1 (CD35), which mediates phagocytosis of C3b/C4b-opsonized immune complexes and erythrocyte-mediated transport.

Biological role and pathway

This variant sits within the CR1 gene, which is involved in the complement receptor / immune complex clearance pathway. Genes within the Immune System & Inflammation cluster work together to maintain balanced function across interconnected biological systems.

Variants in genes within this pathway may influence an individual's predisposition to altered function — particularly under conditions of physiological stress such as viral infection or prolonged illness.

rs6656401 and Long COVID / ME-CFS research

CR1 mediates immune complex clearance; variants (affecting CR1 density) may impair clearance of complement-opsonized SARS-CoV-2 immune complexes and contribute to autoimmune pathology in Long COVID.

This information is based on published research and does not constitute medical advice. See references below.

Parent gene: CR1

rs6656401 is one of 2 known variants in the CR1 gene. To understand the full biological context of this variant, explore the parent gene page.

View CR1 gene page →

Conditions studied in relation to rs6656401

Research into CR1 variants including rs6656401 has explored associations with the following conditions. These are areas of scientific investigation and do not imply causation.

Genetic insights from DNA data

Consumer DNA files from 23andMe, AncestryDNA, and MyHeritage contain raw SNP data. When you upload your file to ChronicDNA, the analysis engine checks your genotype against a curated panel of 80+ genes selected for their relevance to Long COVID, ME/CFS, and connected biological pathways - some of which may include CR1 and the rs6656401 variant.

The report is educational - it explains which variants you carry, what the research says about them, and how they fit into the biological pathways most relevant to chronic illness. Results are presented in plain English with appropriate scientific context, no medical jargon, no scare tactics. All results should be discussed with a qualified healthcare provider.

Other variants in the CR1 gene

The following variants in CR1 are also studied in relation to chronic illness and may be analysed together for a more complete picture.

Frequently asked questions

What is the rs6656401 variant in the CR1 gene?

rs6656401 is a single nucleotide polymorphism (SNP) located in the CR1 (Complement Receptor 1 (CD35)) gene, which is involved in complement receptor / immune complex clearance. CR1 encodes complement receptor 1 (CD35), which mediates phagocytosis of C3b/C4b-opsonized immune complexes and erythrocyte-mediated transport.

How may the rs6656401 variant relate to Long COVID or ME/CFS?

CR1 mediates immune complex clearance; variants (affecting CR1 density) may impair clearance of complement-opsonized SARS-CoV-2 immune complexes and contribute to autoimmune pathology in Long COVID.

Can a consumer DNA test detect the rs6656401 variant?

Many consumer DNA tests such as 23andMe, AncestryDNA, and MyHeritage genotype common SNPs. ChronicDNA analyses your raw DNA file and reports on variants studied in relation to chronic illness, immune function, and metabolism. This is not a diagnostic service — results are informational and educational only.

Find out if you carry the rs6656401 variant

Upload your DNA data from 23andMe, AncestryDNA, or MyHeritage and receive a personalised report covering >80 genes relevant to Long COVID and ME/CFS.

Get Your Personalised DNA Report

Informational and educational only · Not a diagnostic tool · GDPR compliant

References

The following publications were used in compiling the research context for CR1 and its variants. This is not an exhaustive literature review.

  • [1]PMID: 32296168
  • [2]Nature Genetics
  • [3]Journal of Immunology