Analysis of CpG C-to-T mutations in neurofibromatosis type 1. Mutations in brief no. 129. Online.
Neurofibromatosis type 1 (NF1) is a dominant disorder caused by mutations in the NF1 gene; approximately 100 NF1 gene mutations have been published. The CpG C-to-T transition is a frequent mutation mechanism in genetic disorders. To estimate its frequency in NF1, we employed a PCR-restriction digestion method to examine 17 CpGs in 65 patients, and also screened for a CpG nonsense transition (R1947X) that occurs in 1-2% of patients. The analysis revealed disease-related CpG C-to-T transitions (including a nonsense mutation that may be as frequent as R1947X) as well as a benign variant and another mutation at a CpG. Four patients showed CpG mutations in analysis of 18 sites (17 surveyed by restriction digest, plus the R1947X assay), including three C-to-T transitions and one C-to-G transversion. These 18 sites represent one-fifth of the 91 CpGs at which a C-to-T transition would result in a nonsense or nonconservative missense mutation. Thus, it is feasible that the CpG mutation rate at NF1 might be similar to that seen in other disorders with a high mutation rate, and that recurrent NF1 mutations may frequently reside at CpG sites.
Krkljus
S
S
Department of Pediatrics, Division of Genetics, University of Florida, Gainesville, Florida, USA.
Abernathy
C R
CR
Johnson
J S
JS
Williams
C A
CA
Driscoll
D J
DJ
Zori
R
R
Stalker
H J
HJ
Rasmussen
S A
SA
Collins
F S
FS
Kousseff
B G
BG
Baumbach
L
L
Wallace
M R
MR
D003596:Cytosine; D016514:Genes, Neurofibromatosis 1 / Q000235:genetics; D005820:Genetic Testing; D006801:Humans; D009154:Mutation / Q000235:genetics*; D009456:Neurofibromatosis 1 / Q000235:genetics*; D013941:Thymine
D003596:Cytosine; D013941:Thymine