title: Limbal stem cell deficiency and ocular phenotype in ectrodactyly-ectodermal dysplasia-clefting syndrome caused by p63 mutations.
abstract: OBJECTIVE
  To describe the ocular phenotype in patients with ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome (MIM#604292) and to determine the pathogenic basis of visual morbidity.
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  Nineteen families (23 patients) affected by EEC syndrome from the United Kingdom, Ireland, and Italy.
  
  
  METHODS
  General medical examination to fulfill the diagnostic criteria for EEC syndrome and determine the phenotypic severity. Mutational analysis of p63 was performed by polymerase chain reaction-based bidirectional Sanger sequencing. All patients with EEC syndrome underwent a complete ophthalmic examination and ocular surface assessment. Limbal stem cell deficiency (LSCD) was diagnosed clinically on the basis of corneal conjunctivalization and anatomy of the limbal palisades of Vogt. Impression cytology using immunofluorescent antibodies was performed in 1 individual. Histologic and immunohistochemical analyses were performed on a corneal button and corneal pannus from 2 EEC patients.
  
  
  METHODS
  The EEC syndrome phenotypic severity (EEC score), best-corrected Snellen visual acuity (decimal fraction), slit-lamp biomicroscopy, tear function index, tear breakup time, LSCD, p63 DNA sequence variants, impression cytology, and corneal histopathology.
  
  
  RESULTS
  Eleven heterozygous missense mutations in the DNA binding domain of p63 were identified in all patients with EEC syndrome. All patients had ocular involvement and the commonest was an anomaly of the meibomian glands and lacrimal drainage system defects. The major cause of visual morbidity was progressive LSCD, which was detected in 61% (14/23). Limbal stem cell deficiency was related to advancing age and caused a progressive keratopathy, resulting in a dense vascularized corneal pannus, and eventually leading to visual impairment. Histologic analysis and impression cytology confirmed LSCD.
  
  
  CONCLUSIONS
  Heterozygous p63 mutations cause the EEC syndrome and result in visual impairment owing to progressive LSCD. There was no relationship of limbal stem cell failure with the severity of EEC syndrome, as classified by the EEC score, or the underlying molecular defect in p63.
  
  
  BACKGROUND
  The authors have no proprietary or commercial interest in any of the materials discussed in this article.
authors.affiliation: The Veneto Eye Bank Foundation, Venice, Italy.
authors.forename: Enzo
authors.initials: E
authors.lastname: Di Iorio
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Kaye
authors.forename: Diego
authors.initials: D
authors.lastname: Ponzin
authors.forename: Vanessa
authors.initials: V
authors.lastname: Barbaro
authors.forename: Stefano
authors.initials: S
authors.lastname: Ferrari
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Böhm
authors.forename: Paola
authors.initials: P
authors.lastname: Nardiello
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Castaldo
authors.forename: John A
authors.initials: JA
authors.lastname: McGrath
authors.forename: Colin E
authors.initials: CE
authors.lastname: Willoughby
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002971:Cleft Lip / Q000175:diagnosis / Q000235:genetics*; D002972:Cleft Palate / Q000175:diagnosis / Q000235:genetics*; D003316:Corneal Diseases / Q000175:diagnosis / Q000235:genetics* / Q000601:surgery; D004252:DNA Mutational Analysis; D004476:Ectodermal Dysplasia / Q000175:diagnosis / Q000235:genetics*; D004847:Epithelial Cells / Q000473:pathology; D019573:Epithelium, Corneal / Q000473:pathology; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D015948:Keratoplasty, Penetrating; D016850:Limbus Corneae / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D020125:Mutation, Missense; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D013234:Stem Cells / Q000473:pathology*; D014157:Transcription Factors / Q000235:genetics*; D025521:Tumor Suppressor Proteins / Q000235:genetics*; D014786:Vision Disorders / Q000235:genetics; D014792:Visual Acuity / Q000502:physiology
chemical_list: C115051:TP63 protein, human; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins