Neurofibromatosis type 1 (NF1) is one of the most common inherited disorders and is characterized by abnormalities in multiple tissues derived from the neural crest.

We analyzed the presence of mutations of NF1 gene in unrelated 56 Korean NF-1 patients.

Mutations were detected by polymerase chain reaction, single strand conformational polymorphism analysis and direct DNA sequencing.

We found five different kinds of mutations in the NF1 gene from 5 out of 56 unrelated Korean NF1 patients. Sequence analysis revealed a nucleotide substitution at codon 1276 of exon 22 (CGA to TGA, R1276X), 4 by insertion at codon 1270 of exon 22 (3809 ins TGGA), a base pair deletion at codon 1398 of exon 24 (4192 del G), 4 by deletion at codon 1638 of exon 28 (4914 del CTCT), and a base pair substitution at codon 1947 of exon 31 (CGA to TGA, R1947X). All of these mutations resulted in premature termination of the mutant alleles.

Results showed that common consequences of NF1 mutations are introduction of a premature stop codon, and these mutant genes may encode truncated forms of neurofibromin.