Study on mutations of NF1 gene in Chinese

Objective Fifty-six neurofibromatosis type 1 (NF-1) cases from 28 families were screened for mutations in some exons of NF1 gene near NF1-GRD region. In this paper, we studied gene mutation regularity, type, mechanism, and related clinical phenotype in Chinese NF-1 patients in order to find out the potential hotspots of NF1 gene mutation. Methods This study included 56 NF-1 patients. Mutation or polymorphism of exon 20, 28, 29, 39 in these patients were screened by polymerase chain reaction (PCR)-single strand conformation polymorphism (SSCP)/heteroduplex analysis (HA) and further confirmed by DNA sequencing. Results Among 28 families, three NF-1 patients (a father and 2 sons) came from one family with missense mutations for Leu1141Arg of exon 20 T→G heterozygous mutation were found. At first, abnomal mobility shift was detected by SSCP/HA, when the same experiment was repeated, SSCP showed negative result and HA remained abnormal. In another NF-1 patient abnormal mobility shift was detected by SSCP/HA and heterozygous for G→T polymorphism located at-28 nucleotide of exon 28 was found in DNA sequencing. No mutation of exon 29, 39 was seen. Conclusion The combination of PCR-SSCP/HA can increase the sensitivity and positive detectable rate of NF1 gene mutation. Exon 20, 28, 29, 39 are not mutation hotspots or relative high mutation rate regions of NF1 gene in 56 Chinese patients from 28 examined families.