A 2006 genetic study of a large American family (Ikeda et al., 2006) identified genetic linkage between DNA markers on chromosome 11 and the gene producing the autosomal dominant neuromuscular disorder spinocerebellar ataxia type 5 (SCA5). The following lod score data are taken from the 2006 study:
Does either group of lod scores indicate statistically significant odds in favor of genetic linkage? Explain your answer.

Question

A 2006 genetic study of a large American family (Ikeda et al., 2006) identified genetic linkage between DNA markers on chromosome 11 and the gene producing the autosomal dominant neuromuscular disorder spinocerebellar ataxia type 5 (SCA5). The following lod score data are taken from the 2006 study:

Does either group of lod scores indicate statistically significant odds in favor of genetic linkage? Explain your answer.

Lod score data table showing theta values for genetic linkage between SCA5 and DNA markers A and B.

Does either group of lod scores indicate statistically significant odds in favor of genetic linkage? Explain your answer.

Accepted Answer

Hi, everyone. Welcome back. Let's look at our next question. It says a genetic study is carried out to determine the genetic linkage between an autosomal dominant neuromuscular disorder producing gene and DNA markers on a specific chromosome, which of the following logarithm of the odds. L O D score values is considered statistically significant evidence of genetic linkage. And our answer choices are a 0.5 B 1.5 C 2.5 or D 3.5. Well, as we can recall our logarithm of the odds, it's calculated by taking the logarithm of the odds of the loci are linked divided by the odds of the loci are unlinked. And the sort of cut-off point there is that an L O D score of 2.5 or higher is considered statistically significant evidence of linkage. So we can go ahead and eliminate the choices that are lower than 2.5. So eliminate choice A 0.5 and choice B 1.5, a little bit trickier is that decision between 2.5 and 3.5. But the way our question is phrased, which of the following logarithm of the odd score values is considered significantly significant evidence seems to indicate that it wants us to kind of pick that cut off point at what point it does that value indicate statistical significance. So that leads us to choose that choice C 2.5, which is sort of the cut, the, the point at which it's significant rather than choice D 3.5, which is, you know, extremely strong evidence that they're linked more even than we need. So again, which of the following logarithm of the odd score values is considered statistically statistically significant evidence of genetic linkage choice C2.5. See you in the next video.

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Key Concepts

Lod Score

Theta (θ) Value

Autosomal Dominant Inheritance