title: A major segment of the neurofibromatosis type 1 gene: cDNA sequence, genomic structure, and point mutations.
abstract: Overlapping cDNA clones from the translocation breakpoint region (TBR) gene, recently discovered at the neurofibromatosis type 1 locus and found to be interrupted by deletions and a t(17;22) translocation, have been sequenced. A 4 kb sequence of the transcript of the TBR gene has been compared with sequences of genomic DNA, identifying a number of small exons. Identification of splice junctions and a large open reading frame indicates that the gene is oriented with its 5' end toward the centromere, in opposition to the three known active genes in the region. PCR amplification of a subset of the exons, followed by electrophoresis of denatured product on native gels, identified six variant conformers specific to NF1 patients, indicating base pair changes in the gene. Sequencing revealed that one mutant allele contains a T----C transition changing a leucine to a proline; another NF1 allele harbors a C----T transition changing an arginine to a stop codon. These results establish the TBR gene as the NF1 gene and provide a description of a major segment of the gene.
authors.affiliation: Department of Human Genetics, University of Utah School of Medicine, Salt Lake City 84103.
authors.forename: R M
authors.initials: RM
authors.lastname: Cawthon
authors.forename: R
authors.initials: R
authors.lastname: Weiss
authors.forename: G F
authors.initials: GF
authors.lastname: Xu
authors.forename: D
authors.initials: D
authors.lastname: Viskochil
authors.forename: M
authors.initials: M
authors.lastname: Culver
authors.forename: J
authors.initials: J
authors.lastname: Stevens
authors.forename: M
authors.initials: M
authors.lastname: Robertson
authors.forename: D
authors.initials: D
authors.lastname: Dunn
authors.forename: R
authors.initials: R
authors.lastname: Gesteland
authors.forename: P
authors.initials: P
authors.lastname: O'Connell
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002872:Chromosome Deletion; D002886:Chromosomes, Human, Pair 17; D002892:Chromosomes, Human, Pair 22; D003001:Cloning, Molecular; D003360:Cosmids; D004247:DNA / Q000235:genetics*; D005091:Exons; D005796:Genes; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D009154:Mutation; D009456:Neurofibromatosis 1 / Q000235:genetics*; D015345:Oligonucleotide Probes; D016133:Polymerase Chain Reaction; D014158:Transcription, Genetic; D014178:Translocation, Genetic
chemical_list: D015345:Oligonucleotide Probes; D004247:DNA