DNA error rates

Keith Robison robison1 at husc10.harvard.edu
Tue May 19 12:08:26 EST 1992

rbradbur at hardy.u.washington.edu (Robert Bradbury) writes:

>Now, looking at the "Parameters of the Human Genome", NE Morton, PNAS 88:7474-6
>we can see the X chromosome is 5.1% of the genome.  Assuming that we have
>100,000 genes and that one in 10 are "active" in a cell, we must have 500
>active genes on the X chromosome.  Going back to my 2.2*10^-5 mutation rate
>we get 1 in 100 cells with a broken X-chromosome gene.  

Two qualifiers:
Don't forget, not all genes on the X are unpaired with the Y.  A region
called the "pseudoautosomal" region contains paired genes.  Most of these
genes escape X-inactivation.  Also, a few genes which do pair are not
X-inactivated, so in 1/2 the population those genes have extra copies.

Keith Robison
Harvard University
Program in Biochemistry, Molecular, Cellular, and Developmental Biology

robison at ribo.harvard.edu 

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