Transglutaminase-1 mutations in Omani families with lamellar ichthyosis.

[lamellar ichthyosis]

To determine the molecular basis of familial ichthyosis in three Omani families .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 2 q 33 -32 (ABCA 12 ), 14 q 11 (TGM 1 ), and 19 p 12 -q 12 using commercially supplied polymorphic fluorescent microsatellite markers . TGM 1 was analyzed by direct sequencing for disease-associated mutations .Two known pathogenic mutations in TGM 1 were detected : p .Gly 278 Arg in families A and B and p .A rg 396 H is in family C . These two mutations were segregating in an autosomal recessive mode of inheritance .Two known pathogenic TGM 1 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 .