2 FURTHER CASES OF MUTATION R1947X IN THE NF1 GENE - SCREENING FOR A RELATIVELY COMMON RECURRENT MUTATION

We present two further cases of mutation R1947X in the neurofibromatos is type 1 gene. To date, a total of nine cases of mutation R1947X have been reported giving a frequency of about 2% and confirming the recur rence of this mutation. R1947X occurs within a CpG dinucleotide and su pports the hypothesis that the mutation rate for this dinucleotide is higher than that of other dinucleotides. As routine analysis for R1947 X is advisable, we have developed an allele-specific oligonucleotide h ybridization assay for the efficient screening of a large number of sa mples.