Mutation screening of TGFBI in two Iranian Avellino corneal dystrophy pedigrees.
OBJECTIVE
Genetic analysis and phenotypic features of Avellino corneal dystrophy patients from Japan and some European countries have been published. We report for the first time the genetic analysis and phenotypic features of two Avellino corneal dystrophy pedigrees from the Middle East.


METHODS
Slit-lamp biomicroscope photographs of cornea were obtained, and corneal tissue sections were stained with masson-trichrome and Congo red. DNA was isolated from peripheral blood leucocytes and exons 4 and 12 of TGFBI were screened for mutations by direct sequencing.


RESULTS
The probands of the pedigrees had phenotypic features consistent with diagnosis of Avellino corneal dystrophy. They were homozygous for the same R124H mutation in TGFBI as previously reported in Avellino patients from Japan and European countries. Heterozygous carriers of the mutation were identified in the pedigree and shown to have symptoms of disease milder than those of the probands.


CONCLUSIONS
The finding of R124H in the Middle Eastern (Iranian) population supports the proposal that perhaps only substitution of histidine for arginine at position 124 of tumour growth factor beta induced protein results in the Avellino corneal dystrophy phenotype. As both probands were originally diagnosed with granular corneal dystrophy, and as heterozygous carriers of R124H were unaware of their disease status prior to genetic analysis, the importance of genetic analysis is emphasized.
Alavi
Afagh
A
National Institute of Genetic Engineering and Biotechnology, Tehran, Iran.
Elahi
Elahe
E
Rahmati-Kamel
Mohsen
M
Karimian
Farid
F
Rezaei-Kanavi
Mojgan
M
D000225:Adenine; D001120:Arginine; D002648:Child; D002675:Child, Preschool; D003317:Corneal Dystrophies, Hereditary / Q000235:genetics* / Q000473:pathology; D004252:DNA Mutational Analysis; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D005260:Female; D005820:Genetic Testing; D014644:Genetic Variation; D006147:Guanine; D006639:Histidine; D006720:Homozygote; D006801:Humans; D007492:Iran; D008297:Male; D009154:Mutation; D010375:Pedigree; D016212:Transforming Growth Factor beta / Q000235:genetics*; D000099222:betaIG-H3 Protein
D000225:Adenine; D001120:Arginine; D016326:Extracellular Matrix Proteins; D006147:Guanine; D006639:Histidine; D016212:Transforming Growth Factor beta; D000099222:betaIG-H3 Protein