title: Detection and characterization of NF1 microdeletions by custom high resolution array CGH.
abstract: In 5% to 10% of cases, neurofibromatosis type 1 is caused by microdeletions scattered across the entire NF1 gene and various neighboring genes. The phenotype appears to be more severe in patients with NF1 microdeletions than in patients with NF1 single point mutations. We have developed a new method for detecting and characterizing NF1 microdeletions based on a custom high-resolution oligonucleotide array comparative genomic hybridization by using the custom 8x15K Agilent array format. The array comprised a total of 14,207 oligonucleotide probes spanning the whole of chromosome 17, including 12,314 probes spanning an approximately 8 Mb interval surrounding the NF1 locus. We validated this approach by testing NF1 microdeleted DNA samples previously characterized by means of microsatellites and real-time PCR methods. Our array comparative genomic hybridization provided enough information for subsequent long-range PCR and nucleotide sequencing of the microdeletion endpoints. Unlike previously described methods, our array comparative genomic hybridization was able to unambiguously differentiate between the three types of microdeletions (type I, type II, and atypical) and to characterize atypical microdeletions. Further comparative studies of patients with well-characterized genotypes and phenotypes and different microdeletions sizes and breakpoints will help determine whether haploinsufficiency of deleted genes and/or genes rearrangements influence clinical outcomes.
authors.affiliation: UMR745 INSERM, Université Paris Descartes, Faculté des Sciences Pharmaceutiques et Biologiques, 4 avenue de l'Observatoire, 75006 Paris, France. eric.pasmant@etu.univ-paris5.fr
authors.forename: Eric
authors.initials: E
authors.lastname: Pasmant
authors.forename: Audrey
authors.initials: A
authors.lastname: Sabbagh
authors.forename: Julien
authors.initials: J
authors.lastname: Masliah-Planchon
authors.forename: Véronique
authors.initials: V
authors.lastname: Haddad
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: Hamel
authors.forename: Ingrid
authors.initials: I
authors.lastname: Laurendeau
authors.forename: Jean
authors.initials: J
authors.lastname: Soulier
authors.forename: Béatrice
authors.initials: B
authors.lastname: Parfait
authors.forename: Pierre
authors.initials: P
authors.lastname: Wolkenstein
authors.forename: Ivan
authors.initials: I
authors.lastname: Bièche
authors.forename: Michel
authors.initials: M
authors.lastname: Vidaud
authors.forename: Dominique
authors.initials: D
authors.lastname: Vidaud
mesh_terms: D055028:Comparative Genomic Hybridization / Q000379:methods*; D006801:Humans; D018895:Microsatellite Repeats / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009456:Neurofibromatosis 1 / Q000235:genetics; D025542:Neurofibromin 1 / Q000235:genetics*; D016133:Polymerase Chain Reaction
chemical_list: D025542:Neurofibromin 1