title: Prevalence of granular corneal dystrophy type 2 (Avellino corneal dystrophy) in the Korean population.
abstract: OBJECTIVE
  This study investigates the prevalence of granular corneal dystrophy type 2 (GCD2; Avellino corneal dystrophy) in the Korean population.
  
  
  METHODS
  GCD2 homozygotes were identified through a collaboration of Korean referral centers for corneal disease. The genetic status of the patients and their immediate families were verified by DNA analysis. A lower bound for the gene prevalence was calculated using a model based on the Hardy-Weinberg principle. A second population-based model was developed to correct for known underestimation in the primary model. The corrected model used population data from the 2005 Korean census and fertility rates from historical Korean census data.
  
  
  RESULTS
  We identified 21 individuals homozygous for GCD2 (R124H mutation) from 16 Korean families. From this, we estimate that the overall prevalence (combining heterozygotes and homozygotes) is at least 8.25 affected persons/10,000 persons. Our corrected estimate for overall prevalence is 11.5 affected persons/10,000 persons.
  
  
  CONCLUSIONS
  We present the first estimate of the prevalence of GCD2. Although uncommon, the prevalence of GCD2 in Korea is greater than anticipated. We believe that our approach could potentially be applied to estimating the prevalence of other rare diseases.
authors.affiliation: Corneal Dystrophy Research Institute, Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jae Hwan
authors.initials: JH
authors.lastname: Lee
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Cristol
authors.forename: Woon Cho
authors.initials: WC
authors.lastname: Kim
authors.forename: Eui Sang
authors.initials: ES
authors.lastname: Chung
authors.forename: Hungwon
authors.initials: H
authors.lastname: Tchah
authors.forename: Man Soo
authors.initials: MS
authors.lastname: Kim
authors.forename: Chung Mo
authors.initials: CM
authors.lastname: Nam
authors.forename: Hyun-Soo
authors.initials: HS
authors.lastname: Cho
authors.forename: Eung Kweon
authors.initials: EK
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003317:Corneal Dystrophies, Hereditary / Q000453:epidemiology* / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000235:genetics; D005260:Female; D006801:Humans; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D020641:Polymorphism, Single Nucleotide; D015995:Prevalence; D017678:Sex Distribution; D016212:Transforming Growth Factor beta / Q000235:genetics; D055815:Young Adult; D000099222:betaIG-H3 Protein
chemical_list: D016326:Extracellular Matrix Proteins; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein