title: A novel diagnostic method to detect truncated neurofibromin in neurofibromatosis 1.
abstract: Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic condition caused by dominant loss-of-function mutations of the tumor suppressor gene NF1 that encodes neurofibromin, a negative regulator of RAS activity. Mutation analysis of NF1 located at 17q11.2 has been hampered by the large size of the gene, the high rate of new mutations, the lack of mutational clustering, and the presence of several homologous loci. To date, about 80% of the reported NF1 mutations are predicted to result in protein truncation, but very few studies have correlated the causative NF1 mutation with its effect at the protein level. We evaluated a novel diagnostic method to detect truncated forms of neurofibromin in a large cohort of unrelated subjects suspected of having NF1, according to the NIH consensus criteria. Western blot analysis was carried out on protein extracts from patients' leukocytes to highlight the possible presence of altered neurofibromin as a result of mutations in NF1. Truncated neurofibromin was identified in 274/336 patients (81%), confirming the usefulness and reproducibility of the proposed diagnostic approach. Our methodology can be routinely applied in the diagnostic setting, thanks to its simplicity and reliability. Combined with molecular approaches, it may increase the accuracy and efficiency of NF1 genetic testing. We evaluated a novel diagnostic method to detect truncated forms of neurofibromin in patients fulfilling the clinical criteria for Neurofibromatosis 1. Western blot analysis identified truncated neurofibromin in 274/336 patients (81%). Our results indicate that the proposed technique is cheap and reliable, and could ideally be performed as a preliminary biochemical screening before molecular analysis of the NF1 gene.
authors.affiliation: Laboratory of Molecular Genetics, Department of Experimental Medicine section F.Bottazzi, Second University of Naples, Naples, Italy.|Services Dietetics, Department of Experimental Medicine section F.Bottazzi, Second University of Naples, Naples, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Esposito
authors.affiliation: Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Naples, Italy.
authors.forename: Giulio
authors.initials: G
authors.lastname: Piluso
authors.affiliation: Division of Neurology & InterUniversity Center for Research in Neuroscience, Department of Clinical and Experimental Medicine and Surgery, Second University of Naples, Naples, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Saracino
authors.affiliation: Laboratory of Molecular Genetics, Department of Experimental Medicine section F.Bottazzi, Second University of Naples, Naples, Italy.|Division of Neurology & InterUniversity Center for Research in Neuroscience, Department of Clinical and Experimental Medicine and Surgery, Second University of Naples, Naples, Italy.
authors.forename: Rossella
authors.initials: R
authors.lastname: Uccello
authors.affiliation: Division of Neurology & InterUniversity Center for Research in Neuroscience, Department of Clinical and Experimental Medicine and Surgery, Second University of Naples, Naples, Italy.
authors.forename: Carla
authors.initials: C
authors.lastname: Schettino
authors.affiliation: Division of Neurology & InterUniversity Center for Research in Neuroscience, Department of Clinical and Experimental Medicine and Surgery, Second University of Naples, Naples, Italy.
authors.forename: Clemente
authors.initials: C
authors.lastname: Dato
authors.affiliation: Division of Neurology & InterUniversity Center for Research in Neuroscience, Department of Clinical and Experimental Medicine and Surgery, Second University of Naples, Naples, Italy.
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Capaldo
authors.affiliation: Department of Biochemistry, Biophysics and General Pathology, Second University of Naples, Naples, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Giugliano
authors.affiliation: Laboratory of Molecular Genetics, Department of Experimental Medicine section F.Bottazzi, Second University of Naples, Naples, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Varriale
authors.affiliation: Department of Scienze Mediche, Chirurgiche, Neurologiche, Metaboliche e dell'Invecchiamento, Second University of Naples, Naples, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Paolisso
authors.affiliation: Division of Neurology & InterUniversity Center for Research in Neuroscience, Department of Clinical and Experimental Medicine and Surgery, Second University of Naples, Naples, Italy.|Department of Scienze Mediche, Chirurgiche, Neurologiche, Metaboliche e dell'Invecchiamento, Second University of Naples, Naples, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Di Iorio
authors.affiliation: Division of Neurology & InterUniversity Center for Research in Neuroscience, Department of Clinical and Experimental Medicine and Surgery, Second University of Naples, Naples, Italy.|Institute of Biosciences and Bioresources CNR (IBBR-CNR), Naples, Italy.
authors.forename: Mariarosa A B
authors.initials: MA
authors.lastname: Melone
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D004252:DNA Mutational Analysis; D005260:Female; D016514:Genes, Neurofibromatosis 1 / Q000502:physiology; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009456:Neurofibromatosis 1 / Q000175:diagnosis* / Q000378:metabolism*; D025542:Neurofibromin 1 / Q000235:genetics* / Q000378:metabolism*; D015203:Reproducibility of Results; D055815:Young Adult
chemical_list: D025542:Neurofibromin 1
keywords: mutation; neurofibromatosis 1; neurofibromin; stop codon; western blot