title: Transglutaminase-1 mutations in Omani families with lamellar ichthyosis.
abstract: OBJECTIVE
  To determine the molecular basis of familial ichthyosis in three Omani families.
  
  
  METHODS
  Nine patients from three consanguineous families, A, B, and C, were born with typical features of lamellar ichthyosis subtype including collodion membrane and maintained ectropion, and epidermal scaling through their childhood. The 4 patients from family B had more severe symptoms requiring neonatal critical care and subsequent regular treatment with emollients, eye lubricants, and low-dose acitretin. DNA was extracted from peripheral blood by standard methods. The samples were initially genotyped to screen known loci linked to recessive ichthyosis on chromosomes 2q33-32 (ABCA12), 14q11 (TGM1), and 19p12-q12 using commercially supplied polymorphic fluorescent microsatellite markers. TGM1 was analyzed by direct sequencing for disease-associated mutations.
  
  
  RESULTS
  Two known pathogenic mutations in TGM1 were detected: p.Gly278Arg in families A and B and p.Arg396His in family C. These two mutations were segregating in an autosomal recessive mode of inheritance.
  
  
  CONCLUSIONS
  Two known pathogenic TGM1 mutations were detected in three large consanguineous Omani families with lamellar ichthyosis. This study confirmed the geographic distribution of known mutations to an apparently unrelated population.
authors.affiliation: Department of Genetics, Sultan Qaboos University, Al-Khoud, Oman.
authors.forename: Aisha
authors.initials: A
authors.lastname: Al-Naamani
authors.forename: Ahmed
authors.initials: A
authors.lastname: Al-Waily
authors.forename: Mohammed
authors.initials: M
authors.lastname: Al-Kindi
authors.forename: Maha
authors.initials: M
authors.lastname: Al-Awadi
authors.forename: Said Ali
authors.initials: SA
authors.lastname: Al-Yahyaee
mesh_terms: D003241:Consanguinity; D006239:Haplotypes; D006801:Humans; D017490:Ichthyosis, Lamellar / Q000235:genetics*; D018895:Microsatellite Repeats; D009154:Mutation; D009850:Oman / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D012720:Severity of Illness Index; D011503:Transglutaminases / Q000235:genetics*
chemical_list: D011503:Transglutaminases; C105804:transglutaminase 1