Table 1.

Definitions of some commonly used terms

TermDefinition
Complex diseasesCommon multifactorial human disorders caused by a combination of genetic, environmental, and lifestyle factors, many of which are not yet identified.
ExomeThe exome is composed of all of the exons within the genome, the sequences which, when transcribed, remain within the mature RNA after introns are removed by RNA splicing. This includes untranslated regions of mRNA and, importantly, the protein coding sequence.
GWASA now-fundamental approach to analyze genetic sequence variation throughout the genome that correlates alleles to different diseases and traits.
iPSCells derived from skin or blood that are reprogrammed back into an embryonic-like pluripotent state before subsequent development toward a desired human cell type.
Mendelian diseaseDiseases (typically rare) caused by mutations in a single gene that sometimes run in families. Pedigree analyses of large families can determine disease-associated genes on autosomes or on a sex chromosome, and whether the related disease phenotype is dominant (involve damage to only one gene copy) or recessive (involving both gene copies).
PenetranceThe proportion of individuals carrying a particular variant of a gene that also express an associated trait. In medical genetics, the penetrance of a disease-causing mutation is the proportion of individuals with the mutation who exhibit clinical symptoms.
PleiotropicPleiotropy occurs when one gene influences two or more seemingly unrelated phenotypic traits.
PolymorphismA genetic variant within a population, upon which natural selection can operate.
PCSK9An enzyme encoded on chromosome 1 that is causally linked to LDL cholesterol and has emerged as a prototypic genetic target
RNAiBiologic process in which RNA molecules interfere and inhibit gene expression or translation by neutralizing targeted mRNA molecules
UMODAlso known as Tamm–Horsfall protein, UMOD is a large glycoprotein normally found only in the ascending limb of the loop of Henle extending into the very early portion of the distal tubule. It is a major protein of normal urine and is the primary component of waxy nephron casts.
  • GWAS, genome-wide association study; iPS, induced pluripotent stem cells; PCSK9, proprotein convertase subtilisin/klexin type 9; RNAi, RNA interference; UMOD, uromodulin.