title: The rates of G:C-->T:A and G:C-->C:G transversions at CpG dinucleotides in the human factor IX gene.
abstract: We have identified eight independent transversions at CpG in 290 consecutive families with hemophilia B. These eight transversions account for 16.3% of all independent transversions in our sample, yet the expected frequency of CpG transversions at random in the factor IX gene is only 2.6% (P < .01). The aggregate data suggest that the two types of CpG transversions (G:C-->T:A and G:C-->C:G) possess similar mutation rates (24.8 x 10(-10) and 20.6 x 10(-10), respectively), which are about fivefold greater than the comparable rates for transversions at non-CpG dinucleotides. The enhancement of transversions at CpG suggests that the model by which mutations occur at CpG may need to be reevaluated. The relationship, if any, between deamination of 5-methyl cytosine and enhancement of transversions at CpG remains to be defined.
authors.affiliation: Department of Biochemistry and Molecular Biology, Mayo Clinic/Foundation, Rochester, MN 55905.
authors.forename: R P
authors.initials: RP
authors.lastname: Ketterling
authors.forename: E
authors.initials: E
authors.lastname: Vielhaber
authors.forename: S S
authors.initials: SS
authors.lastname: Sommer
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003062:Codon / Q000235:genetics; D015226:Dinucleoside Phosphates / Q000032:analysis; D005164:Factor IX / Q000235:genetics*; D002836:Hemophilia B / Q000097:blood / Q000235:genetics*; D006801:Humans; D008957:Models, Genetic; D008969:Molecular Sequence Data; D017354:Point Mutation; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic
chemical_list: D003062:Codon; D015226:Dinucleoside Phosphates; D005164:Factor IX; C015772:CpG dinucleotide