What is the difference between concordant and discordant in MZ twins?
A twin pair is said to be concordant for a trait if both members show it. For instance, twins are concordant for Alzheimer’s disease if both develop it. They are discordant if one does have the disease but the other does not.
What is discordant monozygotic twins?
Although monozygotic (MZ) twins share the majority of their genetic makeup, they can be phenotypically discordant on several traits and diseases. DNA methylation is an epigenetic mechanism that can be influenced by genetic, environmental and stochastic events and may have an important impact on individual variability.
What does concordance mean in genetics?
The amount of similarity in phenotype between a set of individuals. May be used to refer to the presence of the same trait in both members of a pair of twins. Tags: Molecular Biology.
What is a concordance rate in twin studies?
Formally, the concordance rate is the percent of cases in which both members of a pair have a particular attribute. In a study of the relative influence of genes and environment on a mental illness, for example, the attribute is the particular mental illness, and the pairs studied are usually twins.
What is discordance and concordance?
7. 3. A pair of observations is concordant if the subject who is higher on one variable is also higher on the other variable. A pair of observations is discordant if the subject who is higher on one variable is lower on the other variable.
What are concordant twins?
For example, twins are concordant when both have or both lack a given trait. The ideal example of concordance is that of identical twins. Discordance, in genetics typically means that a similar trait is not shared between twin members.
What means concordance and discordance in the twin diagnostic method?
Why are twins called twins?
They result from the fertilization of a single egg with a single sperm. And as those cells divide and multiply, at some point very early in embryonic growth they split into two individuals. So that you can imagine that the genetic material in these two identical twins is identical to each other, hence the name.
What is difference between monozygotic and dizygotic twins?
Identical twins are also known as monozygotic twins. They result from the fertilization of a single egg that splits in two. In contrast, fraternal, or dizygotic, twins result from the fertilization of two separate eggs during the same pregnancy. They share half of their genes, just like any other siblings.
What is the difference between concordant anddiscordant rates of twin traits?
Discordant rates that are higher than concordant rates express the influence of the environment on twin traits. A twin study compares the concordance rate of identical twins to that of fraternal twins.
What is discordance in twins?
discordant twins Unique to multiple gestations, discordance is the difference in the weights of the fetuses.
What is the difference between concordant and discordant pairs?
If the direction of classifications is the same, the pairs are concordant. For example, both X and Y rate item 1 higher than item 2. If the direction of the classification is not the same, the pair is discordant. For example, X rates item 1 higher than item 2 but Y rates item 1 lower than item 2.
What is the definition of concordant probability?
However, the strict definition is the probability that a pair of individuals will both have a certain characteristic, given that one of the pair has the characteristic. For example, twins are concordant when both have or both lack a given trait.