title: Role of molecular testing in the multidisciplinary diagnostic approach of ichthyosis.
abstract: BACKGROUND
  The term ichthyosis describes a generalized disorder of cornification characterized by scaling and/or hyperkeratosis of different skin regions. Mutations in a broad group of genes related to keratinocyte differentiation and epidermal barrier function have been demonstrated to play a causative role in disease development. Ichthyosis may be classified in syndromic or non-syndromic forms based on the occurrence or absence of extracutaneous signs. In this setting, the diagnosis of ichthyosis is an integrated multistep process requiring a multidisciplinary approach in order to formulate the appropriate diagnostic hypothesis and to address the genetic testing.
  
  
  METHODS
  Due to the complex features of the different ichthyoses and the high number of genes involved we have investigated a group of 64 patients, affected by syndromic and non-syndromic diseases, using Next Generation Sequencing as a new tool for the molecular diagnosis.
  
  
  RESULTS
  Using this innovative molecular approach we were able to find pathogenic mutations in 53 out of 64 patients resulting in 82.8 % total detection rate. An interesting result from the analysis of the data is the high rate of novel sequence variations found compared to known mutations and the relevant rate of homozygous mutations.
  
  
  CONCLUSIONS
  The possibility to analyze a large number of genes associated with various diseases allows to study cases with phenotypes not well-determined, giving the opportunity to make new genotype-phenotype correlation. In some cases there were discrepancies between clinical features and histology or electron microscopy and only molecular analysis allowed to definitively resolve the diagnostic dilemma. The genetic diagnosis of ichthyosis leads to a more accurate and effective genetic counseling, allowing correct evaluation of the risk of recurrence, particularly in families with consanguineous background.
authors.affiliation: Dermatology Unit, Bambino Gesù Children's Hospital, IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy. andrea.diociaiuti@opbg.net.
authors.forename: Andrea
authors.initials: A
authors.lastname: Diociaiuti
authors.affiliation: Dermatology Unit, Bambino Gesù Children's Hospital, IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy. may.elhachem@opbg.net.
authors.forename: May
authors.initials: M
authors.lastname: El Hachem
authors.affiliation: Molecular Genetics Laboratory, Medical Genetics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy. elisa.pisaneschi@opbg.net.
authors.forename: Elisa
authors.initials: E
authors.lastname: Pisaneschi
authors.affiliation: Dermatology Unit, Bambino Gesù Children's Hospital, IRCCS, Piazza S. Onofrio 4, 00165, Rome, Italy. simona.giancristoforo@opbg.net.
authors.forename: Simona
authors.initials: S
authors.lastname: Giancristoforo
authors.affiliation: Molecular Genetics Laboratory, Medical Genetics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy. silvia.genovese@opbg.net.
authors.forename: Silvia
authors.initials: S
authors.lastname: Genovese
authors.affiliation: Molecular Genetics Laboratory, Medical Genetics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy. pietro.sirleto@opbg.net.
authors.forename: Pietro
authors.initials: P
authors.lastname: Sirleto
authors.affiliation: Department of Pathology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy. renata.boldrini@opbg.net.
authors.forename: Renata
authors.initials: R
authors.lastname: Boldrini
authors.affiliation: Molecular Genetics Laboratory, Medical Genetics Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy. adriano.angioni@opbg.net.
authors.forename: Adriano
authors.initials: A
authors.lastname: Angioni
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D005260:Female; D056726:Genetic Association Studies; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D007057:Ichthyosis / Q000175:diagnosis* / Q000235:genetics / Q000378:metabolism; D007223:Infant; D008297:Male; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods*; D055815:Young Adult