Alternative splicing of exons 29 and 30 in the neurofibromatosis type 1 gene.

Alternative splicing of exons 29 and 30 of the human neurofibromatosis type 1 (NF1) gene was detected by reverse transcription/polymerase chain reaction (RT-PCR). Three different isoforms that omitted either one or both exons were identified (ex29-, ex30-, and ex29/30-). The alternatively spliced transcripts exhibited tissue-specific differences, with the ex30- variant apparent only in brain. All three isoforms altered the reading frame and introduced a stop codon in the adjacent downstream exon. Alternative splicing of this region of the NF1 gene also was detected in RNA from rats, although only the ex30- variant was observed. RNA from mice revealed only constitutive expression in this region of the NF1 gene. This study adds a new site of alternative processing to the complex expression of NF1.