A gene comprises a deoxyribonucleic acid (DNA) sequence, including introns, exons and regulatory regions, related to transcription of a given ribonucleic acid (RNA). They provide the template for production of a specific protein.
Some genetic variants that are used in MR as instrumental variables (IVs) are within the coding region of a known gene. When MR is used to test the effect of a product of a known gene (e.g., adiponectin or C-reactive protein) on an outcome, variants in the genes coding that protein are used as IVs. Bias due to horizontal pleiotropy is less likely than with variants whose function is unknown or where the exposure being tested is complex and not a direct gene product (e.g., body mass index or educational attainment).
References
Other terms in 'Useful genetic terms ':
- Allele
- Chromosome
- Cis- and trans-variants
- Copy number variation
- Deoxyribonucleic acid (DNA)
- Genetic variant
- Genotype
- Haplotype
- Heterozygous or Heterozygote
- Homozygous or Homozygote
- Linkage disequilibrium (LD)
- Locus
- Palindromic single nucleotide polymorphism (SNP)
- Polygenic risk score (PRS)
- Polymorphism
- Rare variants
- Single nucleotide polymorphism (SNP)