rs703842

What is the rs703842 variant?

rs703842 is a SNP (single nucleotide polymorphism) in the CYP27B1 (Cytochrome P450 Family 27 Subfamily B Member 1) gene. It belongs to the Vitamin Metabolism category and is part of the Vitamin & Nutrient Metabolism biological cluster. CYP27B1 encodes 1-alpha hydroxylase, the enzyme that converts 25-hydroxyvitamin D to the active form 1,25-dihydroxyvitamin D3.

Biological role and pathway

This variant sits within the CYP27B1 gene, which is involved in the vitamin D activation pathway. Genes within the Vitamin & Nutrient Metabolism 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.

Parent gene: CYP27B1

rs703842 is one of 2 known variants in the CYP27B1 gene. To understand the full biological context of this variant, explore the parent gene page.

Conditions studied in relation to rs703842

Research into CYP27B1 variants including rs703842 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 CYP27B1 and the rs703842 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 CYP27B1 gene

The following variants in CYP27B1 are also studied in relation to chronic illness and may be analysed together for a more complete picture.

Frequently asked questions