Prevalence of granular corneal dystrophy type 2 (Avellino corneal dystrophy) in the Korean population.
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.
Lee
Jae Hwan
JH
Corneal Dystrophy Research Institute, Department of Ophthalmology, Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
Cristol
Stephen M
SM
Kim
Woon Cho
WC
Chung
Eui Sang
ES
Tchah
Hungwon
H
Kim
Man Soo
MS
Nam
Chung Mo
CM
Cho
Hyun-Soo
HS
Kim
Eung Kweon
EK
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
D016326:Extracellular Matrix Proteins; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein