Question

12. Calculate the LOD score for pedigree below, assuming autosomal dominant inheritance, using the maximum likelihood estimation of the recombination fraction. Make a quantitative statement about the evidence for or against linkage (15 points). 4/3 411 411 4/1 4/1 4/1 4/1 4/1 4/1

Answer 1

The solution is given below:

Solution 415 ? 43 ht 411 411 411 411 41 4 11 41 Given Autosomal Maximum dominant inheritance Reombination Monimum recombination function possible = 50.8. =) Recombination frequency - Son = 0.5 seq. with a given linkage value = lepas I LOD score (z) probability of birth probability of birth seq. with no dinkage. Probability if genes are unlinked = 0.25 for each allele. for 8 non-lecombinants -10.25) Probability if genes Grecombinants) are linked = (1-4) o 31-0.50 = 0.045 -for 8- non-recombinants = (0,25) 8 Putting both values in LoD score formula, we get: o long = log2 = 0.

LOD score should be for 3 or two genes higher. to be linked Here, Loo=0 So, the two genes are not linked