heritability

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Related to narrow sense heritability: additive genetic variance

her·i·ta·bil·i·ty

(her'i-tă-bil'i-tē),
1. In psychometrics, a statistical term used to denote the extent of variance of a person's total score or response that is attributable to a presumed genetic component, in contrast to an acquired component.
2. In genetics, a statistical term used to denote the proportion of phenotypic variance due to variance in genotypes that is genetically determined, denoted by the traditional symbol h2.
[see heredity]

heritability

Genetics The likelihood of suffering from a hereditary disease when the defective gene is in a person's gene pool. See Additive genetic variance, Genetic variance, Phenotypic variance, Population.

her·i·ta·bil·i·ty

(her'i-tă-bil'i-tē)
1. psychometrics A statistical term used to denote the extent of variance of a subject's total score or response that is attributable to a presumed genetic component, in contrast to an acquired component.
2. genetics A statistical term used to denote the proportion of phenotypic variance due to variance in genotypes that is genetically determined, denoted by the traditional symbol h2.

heritability (h2)

the proportion of all phenotypic variance in a population that is due to genetic differences and which can be assessed in terms of two main ways, BROAD-SENSE HERITABILITY and NARROW-SENSE HERITABILITY. Heritability is thus a general measure of genetic variation without which SELECTION (both natural and artificial) could not proceed, and is used widely by plant and animal breeders to predict the likely effect of selection. For example, if heritability values for a character are low this indicates high environmental variability, and suggests that the response to selection would not be very rapid.

her·i·ta·bil·i·ty

(her'i-tă-bil'i-tē)
In genetics, a statistical term used to denote the proportion of phenotypic variance due to variance in genotypes that is genetically determined, denoted by the traditional symbol h2.

Patient discussion about heritability

Q. Is Autism hereditary? My 3 year old son has been diagnosed with autism last year. I am now pregnant with my second child and am scared that he will too have autism.

A. There is a higher chance that your additional children will have autism too, however its not a given. Be more alert and notice any early signs that your child may develop.

Q. Is Leukemia hereditary? My Grandpa died of Leukemia when he was 50. I am worried that it might be hereditary. Is it?

A. Overall leukemia is not hereditary but there are rare reports of family clusters, that is, more than one case in a family. Therefore, you should consult your Doctor and tell him about your family's medical history.

Q. Is migraine hereditary? If both my parents suffer from migraines does it mean I can't avoid it?

A. Yes, migraines do have a very strong genetic correlation. However, it does not mean that if both your parents have it, you will have it too for 100%. It means only that you have a much higher risk than the regular population, that does not have migraines in their family, to suffer from this condition.

More discussions about heritability
References in periodicals archive ?
Additive (D), dominance (H) and environmental (E) components of variation and narrow sense heritability estimates of various quantitative traits for cross PARI-73 x V-7682 wheat genotypes.
In this study, narrow sense heritability for RSG and RGR groups of lines was 24.90 and 21.21 per cent respectively.
The broad and narrow sense heritability was 97.5% depicting that the character is highly heritable in this irrigation treatment and quite a significant amount of improvement is expected to be brought about while selecting the genotypes/hybrid combinations under high selection pressure from the progeny rows.
Estimates of broad sense and narrow sense heritability were calculated for seed Zn concentration by using the variance of the parent, [F.sub.1][F.sub.2], and backcross generations to estimate phenotypic ([V.sub.P]), environmental ([V.sub.E]), total genetic ([V.sub.G]), additive genetic ([V.sub.A]), and dominance genetic variances ([V.sub.D]).
The significant realized heritability estimates were in close agreement with the (mostly) nonsignificant estimates of narrow sense heritability from the sib-analysis (Table 3).
Narrow sense heritability assesses the extent of additive genotypic variation which is primarily responsible for modifying the genetic makeup of a population.
To ascertain expected genetic gain per selection cycle, we calculated narrow sense heritability estimates.
The narrow sense heritability of corolla length in an annual Phlox was 0.14 (Schwaegerle and Levin 1991), lower than the estimates obtained here from half-sib analysis ([h.sup.2] [is greater than or equal to] 0.24-0.67).
Narrow sense heritability (h2ns) was also calculated using the components of variance from the best-fit model of weighted least squares analysis (Mather and Jinks, 1982).
Abbreviations: [H.sub.ns] = narrow sense heritability; RIL, recombinant inbred line.
Population density can greatly affect the response to selection (Charlesworth, 1971; Mueller et al., 1991), which is the product of narrow sense heritability ([h.sup.2]) times selection differential (Maynard Smith, 1989).
In crop plants, generally, heritability estimates in broad sense are higher than narrow sense because narrow sense heritability uses only additive genetic variance as a numerator over the total phenotypic variance.