title: Mutational analysis of the PTPN11 gene in Egyptian patients with Noonan syndrome.
abstract: OBJECTIVE
  Noonan syndrome (NS) is inherited as an autosomal dominant disorder with dysmorphic facies, short stature, and cardiac defects, which can be caused by missense mutations in the protein tyrosine phosphatase nonreceptor type 11 (PTPN11) gene, which encodes src homology region 2 domain containing tyrosine phosphatase-2 (SHP-2), a protein tyrosine phosphatase that acts in signal transduction downstream to growth factors and cytokines. The current study aimed to study the molecular characterization of the PTPN11 gene among Egyptian patients with Noonan syndrome.
  
  
  METHODS
  Eleven exons of the PTPN11 gene were amplified and screened by single stranded conformational polymorphism (SSCP). DNA samples showing band shift in SSCP were subjected to sequencing.
  
  
  RESULTS
  Mutational analysis of the PTPN11 gene revealed T→C transition at position 854 in exon 8, predicting Phe285Ser substitution within PTP domain of SHP-2 protein, in one NS patient and -21C→T polymorphism in intron 7 in four other cases.
  
  
  CONCLUSIONS
  Knowing that NS is phenotypically heterogeneous, molecular characterization of the PTPN11 gene should serve to establish NS diagnosis in patients with atypical features, although lack of a mutation does not exclude the possibility of NS.
authors.affiliation: Medical Molecular Genetics Department, National Research Center, Giza, Egypt. Electronic address: mlessawi@yahoo.com.
authors.forename: Mona L
authors.initials: ML
authors.lastname: Essawi
authors.forename: Manal F
authors.initials: MF
authors.lastname: Ismail
authors.forename: Hanan H
authors.initials: HH
authors.lastname: Afifi
authors.forename: Maha M
authors.initials: MM
authors.lastname: Kobesiy
authors.forename: Ahmed
authors.initials: A
authors.lastname: El Kotoury
authors.forename: Maged M
authors.initials: MM
authors.lastname: Barakat
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004247:DNA / Q000235:genetics*; D004252:DNA Mutational Analysis / Q000379:methods*; D004534:Egypt / Q000453:epidemiology; D005091:Exons; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D020125:Mutation, Missense; D009634:Noonan Syndrome / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D016133:Polymerase Chain Reaction; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11 / Q000235:genetics* / Q000378:metabolism; D055815:Young Adult
chemical_list: D004247:DNA; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11
keywords: Egyptian patients; Noonan syndrome; PTPN11; SHP-2; mutational analysis