Molecular diagnosis of neurofibromatosis type 1: 2 years experience
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Our experience of providing an NF1 gene diagnostic mutation detection service as part of the UK Genetic Testing Network (UKGTN) is presented. A total of 169 unrelated individuals suspected of having neurofibromatosis type I (NF1) were referred for NF1 diagnostic testing over a 2 year period. Mutation analysis of the entire NF1 coding region and the flanking splice sites was carried out, and included the use of a combination of FISH, dHPLC and MLPA. Possible disease causing mutations were identified in 109 (64%) cases. These comprised 88 different sequence alterations, of which 57 were novel. Out of the 169 cases referred, there were 102 patients with reliable clinical data, of whom 78 satisfied the NIH diagnostic criteria for NF1. Within this better defined cohort of NF1 patients, NF1 mutations were identified in 61 individuals (78%), showing the importance of clinical selection on overall test sensitivity, and highlighting the problem of full clinical data collection in the audit of routine services. As mutation detection technologies advance, facilitating direct sequencing of all coding and flanking non-coding regions of the NF1 gene, the development of an even more cost-effective, quick and sensitive diagnostic test for future testing of NF1 is discussed.
KeywordsDenaturing High Performance Liquid Chromatography (dHPLC) Fluorescence In-Situ Hybridisation (FISH) Multiplex Ligation-Dependent Probe Amplification (MLPA) Mutation Neurofibromatosis Type 1 (NF1) Polymerase chain reaction (PCR) Polymorphism Sequencing UK Genetic Testing Network (UKGTN)
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We thank all the clinicians for their help in providing the clinical information. We are grateful to the Wales Gene Park for their financial support, and the staff of the Molecular Genetics Laboratory of the All-Wales Genetics Laboratory Service. We thank Dr Nick Thomas for his help with the splice prediction program.We wish to thank Dr Susan Huson for her support in initially setting up a diagnostic service, Linda Selwood for her administrative support and Andrew Wallace for developing MLPA data analysis spreadsheets.
- 1.Upadhyaya M, Cooper DN (1998) Neurofibromatosis Type 1 from genotype to phenotype. In: Upadhyaya M, Cooped DN (eds) BIOS Scientific, Oxford Google Scholar
- 3.Huson SM, Hughes RAC (1994) The neurofibromatoses: a pathogenetic and clinical overview. Chapman and Hall Medical, LondonGoogle Scholar
- 5.Purandare SM, Huntsman Breidenbach H, Li Y, Zhu XL, Sawada S, Neil SM, Brothman A, White R, Cawthon R, Viskochil D (1995) Identification of neurofibromatosis 1 (NF1) homologous loci by direct sequencing, fluorescence in situ hybridization, and PCR amplification of somatic cell hybrids. Genomics 30(3):476–485PubMedCrossRefGoogle Scholar
- 10.NIH (1988) NIH Consensus development conference statement. Neurofibromatosis. Arch Neurol 45:575–8Google Scholar
- 14.Viskochil DH (1998) Gene structure and expression. In: Upadhyaya M, Cooper DN (eds) Neurofibromatosis Type 1 from genotype to phenotype. BIOS Scientific, OxfordGoogle Scholar
- 17.Upadhyaya M, Han S, Consoli C, Majounie E, Horan M, Thomas NS, Potts C, Griffiths S, Ruggieri M, von Deimling A, Cooper DN (2004) Characterization of the somatic mutational spectrum of the neurofibromatosis type 1 (NF1) gene in neurofibromatosis patients with benign and malignant tumors. Hum Mutat 23(2):134–146PubMedCrossRefGoogle Scholar
- 19.Fahsold R, Hoffmeyer S, Mischung C, Gille C, Ehlers C, Kucukceylan N, Abdel-Nour M, Gewies A, Peters H, Kaufmann D, Buske A, Tinschert S, Nurnberg P (2000) Minor lesion mutational spectrum of the entire NF1 gene does not explain its high mutability but points to a functional domain upstream of the GAP-related domain. Am J Hum Genet 66(3):790–818PubMedCrossRefGoogle Scholar
- 27.Mattocks C, Baralle D, Tarpey P, ffrench-Constant C, Bobrow M, Whittaker J (2004) Automated comparative sequence analysis identifies mutations in 89% of NF1 patients and confirms a mutation cluster in exons 11–17 distinct from the GAP related domain. J Med Genet 41(4):e48PubMedCrossRefGoogle Scholar
- 39.Origone P, Bellini C, Sambarino D, Banelli B, Morcaldi G, La Rosa C, Stanzial F, Castellan C, Coviello DA, Garre C, Bonioli E (2003) Neurofibromatosis type 1 (NF1): Identification of eight unreported mutations in NF1 gene in Italian patients [corrected]. Hum Mutat 22(2):179–180PubMedCrossRefGoogle Scholar
- 40.Mantripragada KK, Thuresson AC, Piotrowski A, Diaz de Stahl T, Menzel U, Grigelionis G, Ferner RE, Griffiths S, Bolund L, Mautner V, Nordling M, Legius E, Vetrie D, Dahl N, Messiaen L, Upadhyaya M, Bruder CE, Dumanski JP (2006 Jan) Identification of novel deletion breakpoints bordered by segmental duplications in the NF1 locus using high-resolution array-CGH. J Med Genet 43(1):28–38CrossRefGoogle Scholar
- 44.Korf BR (1998) The NF1 genetic analysis consortium. In: Upadhyaya M, Cooper DN (eds) Neurofibromatosis Type 1 from genotype to phenotype. BIOS Scientific, OxfordGoogle Scholar
- 53.DeLuca A, Bottillo I, Sarkozy A, Carta C, Neri C, Bellacchio E, Schirinzi A, Conti E, Zampino G, Battaglia A, Majore S, Rinaldi MM, Cavella M, Marion B, Pizzuti A, Digilio MC, Tartaglia M, Dallapiccola B (2005 Dec NF1 gene mutations represent the major molecular event underlying Neurofibromatosis Noonan syndrome. Am J Hum Genet 77(6):1092–1101CrossRefGoogle Scholar
- 54.Lamlum H, Ilyas M, Rowan A, Clark S, Johnson V, Bell J, Frayling I, Efstathiou J, Pack K, Payne S, Roylance R, Gorman P, Sheer D, Neale K, Phillips R, Talbot I, Bodmer W, Tomlinson I (1999) The type of somatic mutation at APC in familial adenomatous polyposis is determined by the site of the germline mutation: a new facet to Knudson’s ‘two-hit’ hypothesis. Nat Med 5(9):1071–1075PubMedCrossRefGoogle Scholar
- 56.Upadhyaya M, Ruggieri M, Maynard J, Osborn M, Hartog C, Mudd S, Penttinen M, Cordeiro I, Ponder M, Ponder BA, Krawczak M, Cooper DN (1998) Gross deletions of the neurofibromatosis type 1 (NF1) gene are predominantly of maternal origin and commonly associated with a learning disability, dysmorphic features and developmental delay. Hum Genet 102(5):591–597PubMedCrossRefGoogle Scholar