rs1143668
Variant in the MMAB gene (Metabolism Of Cobalamin Associated B)
rs1143668 is a single nucleotide polymorphism (SNP) in the MMAB gene, involved in B12 (cobalamin) metabolism. 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 rs1143668 variant?
rs1143668 is a SNP (single nucleotide polymorphism) in the MMAB (Metabolism Of Cobalamin Associated B) gene. It belongs to the Metabolic category and is part of the Methylation & Neurotransmitters biological cluster. MMAB encodes an enzyme required for the synthesis of adenosylcobalamin (AdoB12), the cofactor for MUT.
Biological role and pathway
This variant sits within the MMAB gene, which is involved in the B12 (cobalamin) metabolism pathway. Genes within the Methylation & Neurotransmitters 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.
rs1143668 and Long COVID / ME-CFS research
MMAB variants affecting adenosylcobalamin synthesis may impair MUT activity and contribute to abnormal organic acid metabolism in Long COVID neurological presentations.
This information is based on published research and does not constitute medical advice. See references below.
Parent gene: MMAB
rs1143668 is one of 2 known variants in the MMAB gene. To understand the full biological context of this variant, explore the parent gene page.
View MMAB gene page →Conditions studied in relation to rs1143668
Research into MMAB variants including rs1143668 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 MMAB and the rs1143668 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 MMAB gene
The following variants in MMAB are also studied in relation to chronic illness and may be analysed together for a more complete picture.
Frequently asked questions
What is the rs1143668 variant in the MMAB gene?
rs1143668 is a single nucleotide polymorphism (SNP) located in the MMAB (Metabolism Of Cobalamin Associated B) gene, which is involved in B12 (cobalamin) metabolism. MMAB encodes an enzyme required for the synthesis of adenosylcobalamin (AdoB12), the cofactor for MUT.
How may the rs1143668 variant relate to Long COVID or ME/CFS?
MMAB variants affecting adenosylcobalamin synthesis may impair MUT activity and contribute to abnormal organic acid metabolism in Long COVID neurological presentations.
Can a consumer DNA test detect the rs1143668 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 rs1143668 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.
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References
The following publications were used in compiling the research context for MMAB and its variants. This is not an exhaustive literature review.
- [1]PMID: 34316049
- [2]Nature Genetics
- [3]AJHG