6_Complex Inheritance Ch. 7 Bio025

Ch. 7 Human Genetics, Lewis

affected sibling pair study

A gene identification approach that looks for single nucleotide polymorphisms (SNPs) that siblings with a particular trait share, but that siblings who do not have the trait do not share.

coefficient of relatedness

The proportion of genes that two people related in a certain way share.

complex trait

A phenotype that is either monogenic or polygenic, and influenced by the environment.

concordance

A measure indicating the degree to which a trait is inherited; percentage of twin pairs in which both members express a trait.

copy number variant (CNV)

A DNA sequence present in different numbers of copies (repeats) in different individuals.

empiric risk

Probability that a trait will recur based upon its incidence in a population, based on observation.

genome-wide association study (GWAS)

Comparison of millions of variants (single nucleotide polymorphisms or copy number variants) that form haplotypes between people with a condition and unaffected individuals to identify parts of the genome that might contribute to a phenotype.

heritability

An estimate of the proportion of phenotypic variation in a population that is due to genetic differences.

homozygosity mapping

Correlation of stretches of homozygous DNA base sequences in the genomes of related individuals to certain traits or disorders.

incidence

The number of new cases of a disease during a certain time in a population.

Manhattan Plot

A graphical representation used in genome-wide association studies to display the (p-values of)associations between genetic variants and traits, showing significant findings as points above a certain threshold.

polygenic

A trait determined by more than one gene.

polygenic risk score

A test of single base differences in several genes derived from people with a specific condition that is then used to identify people in another group who are at high risk of developing the condition.

Prevalence

The number of cases of a disease in a population at a particular time.

single nucleotide polymorphism (SNP)

A site in the DNA that has a different base in at least 1 percent of a population

correlation

A measure of how two factors change together, showing if a change in one is linked to a change in another.

causation

The relationship between two events where one event causes the other to occur.