The Study On Mutation Detection On Exon 32,33 Of NF1 Gene

Objective Using Polymerase chain reaction- single strand conformation polymorphism (PCR-SSCP), we detected mutations in exon 32~ exon 33 of translocation breakpoint region in NFl gene and expected to explore the hot spot of the mutation of NFl gene in Chinese. Methods According to the diagnostic criterion made by NIH in 1987, we have collected 14 families and 62 patients with NF I and their relations, as well as a group comprising 30 controls. The genomic DNA were extracted from leukocyte of the patients, their relations, and controls, according to usual extraction of phenol/chloroform. Consulting the reports, we designed two pairs of primers, which were amplificated exon 32 and exon 33 with PCR. The segments of PCR amplification were 314bp and 462bp separately. The PCR products of exon 32 ~. 33 were denatured with formamide and then applied to 8 00 and 5 % neutral polyacrylamide gel. Electrophoresis was performed for 1 Oh and 12h separately. Following electrophoresis, the gels were stained with silver and the results analyzed. Results There were two peculiar PCR amplification products of exon32 (3 l4bp) and exon 33 (462bp) of NFl gene in all of the patients and controls. Through the detection of exon 32 of NF 1 gene, we had found the mobility shift from DNA SSCP of the probands of pedigree B~ D and two NFl patients in pedigree E. The signs in NFL patients with the mutation of exon 32 of NFl gene were extremely broad. Using three different conditions of PCR-SSCP, we hadn抰 found the mobility shift from DNA SSCP on exon 33 of NFl gene. 3 Conclusion 1 -. Exon 32 may be one of hot spots of mutations of NF 1 gene in Chinese. 2 The signs in Nil patients with the mutation of exon 32 of NF I gene are extremely broad. 3~ We haven抰 found the mobility shift of the mutation on exon 33 of NFl gene, which is the same to the report in western countries.