Mutation analysis on exon 20,28,29 and 39 of NF1 gene in Chinese

Objective To perform mutation analysis on exon 20,28,29 and 39 of neurofibromatosis type 1(NF1)gene in Chinese and assess the value ofpolymerase chain reaction-single strand conformation polymorphism/heteroduplex analysis(PCR-SSCP/HA)techniques in gene diagnosis ofNF1.Methods DNA sequencing in addition to PCR-SSCP/HA techniques were applied to screen the mutation or polymorphism in exon 20,28,29 and 39 of NF1 gene in 56 patients.Results Abnormal mobility shift of SSCP/HA detected in exon 20 of familial three men(including the father and his two sons)showed by DNA sequencing that heterozygous T→G mutation in exon 20 was Leu1141Arg mutation;abnormal mobility shift of SSCP/HA detected in exon 28 of one patient showed by DNA sequencing heterozygous G→T mutation located at nucleotide-28(nt-28)of the 5' upstream region in exon 28;no band with abnormal mobility shift was found by SSCP/HA for exon 29 and 39.Conclusion The combined application of SSCP/HA techniques may enhance the sensitivity and detection rate of gene mutations.Exon 20,28,29 and 39 of NF1 gene are not hotspots of mutations or regions with relatively high mutation rate.