title: NF1 microduplications: identification of seven nonrelated individuals provides further characterization of the phenotype.
abstract: OBJECTIVE
  Neurofibromatosis, type 1 (NF1) is an autosomal dominant disorder caused by mutations of the neurofibromin 1 (NF1) gene at 17q11.2. Approximately 5% of individuals with NF1 have a 1.4-Mb heterozygous 17q11.2 deletion encompassing NF1, formed through nonallelic homologous recombination (NAHR) between the low-copy repeats that flank this region. NF1 microdeletion syndrome is more severe than NF1 caused by gene mutations, with individuals exhibiting facial dysmorphisms, developmental delay (DD), intellectual disability (ID), and excessive neurofibromas. Although NAHR can also cause reciprocal microduplications, reciprocal NF1 duplications have been previously reported in just one multigenerational family and a second unrelated proband.
  
  
  METHODS
  We analyzed the clinical features in seven individuals with NF1 microduplications, identified among 48,817 probands tested in our laboratory by array-based comparative genomic hybridization.
  
  
  RESULTS
  The only clinical features present in more than one individual were variable DD/ID, facial dysmorphisms, and seizures. No neurofibromas were present. Three sets of parents were tested: one duplication was apparently de novo, one inherited from an affected mother, and one inherited from a clinically normal father.
  
  
  CONCLUSIONS
  This is the first report comparing the phenotypes of nonrelated individuals with NF1 microduplications. This comparison will allow for further definition of this emerging microduplication syndrome.
authors.affiliation: Signature Genomic Laboratories, PerkinElmer Inc., Spokane, Washington, USA.
authors.forename: Kimberly J
authors.initials: KJ
authors.lastname: Moles
authors.forename: Gordon C
authors.initials: GC
authors.lastname: Gowans
authors.forename: Satyanarayana
authors.initials: S
authors.lastname: Gedela
authors.forename: David
authors.initials: D
authors.lastname: Beversdorf
authors.forename: Arthur
authors.initials: A
authors.lastname: Yu
authors.forename: Laurie H
authors.initials: LH
authors.lastname: Seaver
authors.forename: Roger A
authors.initials: RA
authors.lastname: Schultz
authors.forename: Jill A
authors.initials: JA
authors.lastname: Rosenfeld
authors.forename: Beth S
authors.initials: BS
authors.lastname: Torchia
authors.forename: Lisa G
authors.initials: LG
authors.lastname: Shaffer
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D002658:Developmental Disabilities / Q000235:genetics; D005260:Female; D020440:Gene Duplication; D016514:Genes, Neurofibromatosis 1; D059765:Homologous Recombination; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000235:genetics; D008297:Male; D009455:Neurofibroma / Q000235:genetics; D009456:Neurofibromatosis 1 / Q000175:diagnosis* / Q000235:genetics*; D025542:Neurofibromin 1 / Q000235:genetics*; D010641:Phenotype; D056916:Segmental Duplications, Genomic / Q000235:genetics; D017384:Sequence Deletion; D055815:Young Adult
chemical_list: D025542:Neurofibromin 1