TY - JOUR
T1 - Association and familial segregation of CTG18.1 trinucleotide repeat expansion of TCF4 gene in fuchs' endothelial corneal dystrophy
AU - Mootha, Venkateswara
AU - Gong, Xin
AU - Ku, Hung Chih
AU - Xing, Chao
PY - 2014/1/2
Y1 - 2014/1/2
N2 - PURPOSE. We tested the association between two intronic polymorphisms (CTG18.1 and rs613872) in TCF4 and Fuchs' endothelial corneal dystrophy (FECD), and analyzed their segregation patterns in families. METHODS. We recruited 120 unrelated Caucasian subjects with FECD and 100 controls. Available family members of probands were recruited. Genotyping of the single nucleotide polymorphism (SNP) rs613872 was performed using Sanger sequencing or real-time allelic discrimination assay. The trinucleotide repeat polymorphism, CTG18.1, was genotyped using a combination of short tandem repeat assay and triplet repeat primed PCR assay. The cytosinethymine- guanine (CTG) repeat length of ≥40 was classified as an expanded CTG18.1 allele. Association of the two loci with FECD was evaluated. Segregation in 29 families was examined. RESULTS. The two polymorphisms are in linkage disequilibrium (r2 = 0.65 in cases and 0.31 in controls). Significant associations were found between FECD and rs613872 (P = 3.1 ×10-17), expanded CTG18.1 allele (P = 6.5 ×10-25), and their haplotypes (P = 5.9 ×10-19). The odds ratio (OR) of each copy of the rs613872 G allele for FECD was estimated to be 9.5 (95% confidence interval [CI], 5.1-17.5). The OR of each copy of the CTG18.1 expanded allele was estimated to be 32.3 (95% CI, 13.4-77.6). The expanded CTG 18.1 allele cosegregated with the trait in 52% (15/29) of families with complete penetrance and 10% (3/29) with incomplete penetrance. CONCLUSIONS. We report, to our knowledge, the first independent replication of the expanded CTG 18.1 allele conferring significant risk for FECD (>30-fold increase). The expanded allele cosegregates with the trait with complete penetrance in a majority of families, but we also document cases of incomplete penetrance.
AB - PURPOSE. We tested the association between two intronic polymorphisms (CTG18.1 and rs613872) in TCF4 and Fuchs' endothelial corneal dystrophy (FECD), and analyzed their segregation patterns in families. METHODS. We recruited 120 unrelated Caucasian subjects with FECD and 100 controls. Available family members of probands were recruited. Genotyping of the single nucleotide polymorphism (SNP) rs613872 was performed using Sanger sequencing or real-time allelic discrimination assay. The trinucleotide repeat polymorphism, CTG18.1, was genotyped using a combination of short tandem repeat assay and triplet repeat primed PCR assay. The cytosinethymine- guanine (CTG) repeat length of ≥40 was classified as an expanded CTG18.1 allele. Association of the two loci with FECD was evaluated. Segregation in 29 families was examined. RESULTS. The two polymorphisms are in linkage disequilibrium (r2 = 0.65 in cases and 0.31 in controls). Significant associations were found between FECD and rs613872 (P = 3.1 ×10-17), expanded CTG18.1 allele (P = 6.5 ×10-25), and their haplotypes (P = 5.9 ×10-19). The odds ratio (OR) of each copy of the rs613872 G allele for FECD was estimated to be 9.5 (95% confidence interval [CI], 5.1-17.5). The OR of each copy of the CTG18.1 expanded allele was estimated to be 32.3 (95% CI, 13.4-77.6). The expanded CTG 18.1 allele cosegregated with the trait in 52% (15/29) of families with complete penetrance and 10% (3/29) with incomplete penetrance. CONCLUSIONS. We report, to our knowledge, the first independent replication of the expanded CTG 18.1 allele conferring significant risk for FECD (>30-fold increase). The expanded allele cosegregates with the trait with complete penetrance in a majority of families, but we also document cases of incomplete penetrance.
KW - Fuchs' dystrophy
KW - Genetics
KW - TCF4
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U2 - 10.1167/iovs.13-12611
DO - 10.1167/iovs.13-12611
M3 - Article
C2 - 24255041
AN - SCOPUS:84891657736
SN - 0146-0404
VL - 55
SP - 33
EP - 42
JO - Investigative Ophthalmology and Visual Science
JF - Investigative Ophthalmology and Visual Science
IS - 1
ER -