Heterozygosity & segmental dulications - (Apr/12/2011 )

Hi!Do you know why the heterozygosity reported for the SNPs (for example in dbSNP) it's never higher than 0.5 while for the microsatellite markers often it is reported an heterozygosity of also (for example)0.8? why in general the SNPs have an heterozygosity lower than microsatellite markers?

Another question: I read that segmental duplications often cause chromosomal rearrangements by non allelic homologous recombination. These repeats are present also in the healthy population, so why they cause rarrangements only in some individuals?How it's possible?



Thank you very much!

Sorry, but I have another big doubt: I read that breakpoint of NHEJ-mediated rearrangements often fall within repetitive elements such Alu, LTR...I don't understand how a repetitive element such Alu could mediate a NHEJ event?It's true that region of microhomology could mediate a rearrangement by NHEJ?

Thank you so much!