title: Immunophenotypes of macular corneal dystrophy in India and correlation with mutations in CHST6.
abstract: OBJECTIVE
  To determine the immunophenotypes of macular corneal dystrophy (MCD) in Indian patients and to correlate them with mutations in the carbohydrate 6-sulfotransferase (CHST6) gene.
  
  
  METHODS
  Sixty-four patients from 53 families with MCD that were previously screened for mutations in CHST6 were included in an immunophenotype analysis. Antigenic keratan sulfate (AgKS) in serum as well as corneal tissue was evaluated in 31 families. Only cornea was evaluated in 11 families, and only serum was evaluated in 11 families. AgKS was detected in formalin-fixed, paraffin-embedded corneal sections by immunohistochemistry and in serum by ELISA using a monoclonal antibody against sulfated forms of KS in patients with MCD as well as normal controls.
  
  
  RESULTS
  Analysis of corneal and/or serum AgKS disclosed MCD type I (27 families), MCD type IA (5 families), and MCD type II (3 families) in the cases studied. An additional 10 families were either MCD type I or MCD type IA since only serum AgKS data were available. Seven families manifested atypical immunophenotypes since the corneal AgKS expression was either of MCD type I or MCD type IA, but serum AgKS levels ranged from 19 ng/ml to 388 ng/ml. More than one immunophenotype was detected amongst siblings in two families. Each immunophenotype was associated with mutational heterogeneity in CHST6.
  
  
  CONCLUSIONS
  MCD type I was the predominant immunophenotype in the Indian population studied followed by MCD type IA and then MCD type II. We detected further immunophenotypic heterogeneity by finding atypical patterns of AgKS reactivity in a subset of families. There were no simple correlations between immunophenotypes and specific mutations in CHST6, suggesting that factors other than CHST6 mutations may be contributing to the immunophenotypes in MCD.
authors.affiliation: Kallam Anji Reddy Molecular Genetics Laboratory, Hyderabad Eye Research Foundation, L.V. Prasad Eye Institute, Hyderabad, India.
authors.forename: Afia
authors.initials: A
authors.lastname: Sultana
authors.forename: Gordon K
authors.initials: GK
authors.lastname: Klintworth
authors.forename: Eugene J-M A
authors.initials: EJ
authors.lastname: Thonar
authors.forename: Geeta K
authors.initials: GK
authors.lastname: Vemuganti
authors.forename: Chitra
authors.initials: C
authors.lastname: Kannabiran
mesh_terms: D003315:Cornea / Q000276:immunology / Q000473:pathology; D003317:Corneal Dystrophies, Hereditary / Q000235:genetics* / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D005190:Family; D006801:Humans; D007150:Immunohistochemistry; D007194:India; D007632:Keratan Sulfate / Q000032:analysis / Q000097:blood / Q000276:immunology*; D009154:Mutation; D010641:Phenotype; D013223:Statistics as Topic; D015238:Sulfotransferases / Q000235:genetics* / Q000378:metabolism; D000097811:Carbohydrate Sulfotransferases
chemical_list: D007632:Keratan Sulfate; D015238:Sulfotransferases; D000097811:Carbohydrate Sulfotransferases