COL1A1 and COL2A1 genes and myopia susceptibility: evidence of association and suggestive linkage to the COL2A1 locus.
OBJECTIVE
Collagen involvement in myopia development via scleral remodeling is well-known. Recently, COL1A1 and COL2A1 gene polymorphisms were reported to be associated with high-grade and common myopia, respectively. This study was conducted to investigate whether these collagen genes are associated and/or genetically linked with myopia in large Caucasian family datasets.


METHODS
High-grade myopia was defined as <or=-5.00 D. Two independent datasets comprising 146 (Duke) and 130 (Cardiff) families with high-grade myopia participated in the association study. Allelic discrimination assays were performed on tagging SNPs for COL1A1 and COL2A1. The pedigree disequilibrium test (PDT) and the association test in the presence of linkage (APL) were used for association analyses. Linkage analyses for COL2A1 locus markers were performed with the Fastlink and Merlin programs in conjunction with data obtained from our collaborative whole-genome linkage study (254 families).


RESULTS
Significant association was identified between five SNPs (rs1034762, rs1635529, rs1793933, rs3803183, and rs17122571) of the COL2A1 locus and high-grade myopia (P < 0.045, minimum (min) P = 0.008) and with myopia status set at <or=-0.50 or -0.75 D (min P = 0.004) in the Duke dataset. The SNP rs1635529 also showed significant association in the Cardiff dataset (<or=-5.00 D, min P = 0.004; <or=-0.50 D, min P = 0.007). Linkage analyses showed suggestive linkage to the COL2A1 locus on 12q. No association was found between COL1A1 SNPs and any degree of myopia.


CONCLUSIONS
The COL2A1 gene was associated with high-grade myopia in two independent Caucasian family datasets. COL1A1 gene polymorphisms were not associated with myopia in our dataset, indicating possible heterogeneity across different ethnicities.
Metlapally
Ravikanth
R
Center for Human Genetics, North Carolina, USA.
Li
Yi-Ju
YJ
Tran-Viet
Khanh-Nhat
KN
Abbott
Diana
D
Czaja
Gregory R
GR
Malecaze
Francois
F
Calvas
Patrick
P
Mackey
David
D
Rosenberg
Thomas
T
Paget
Sandrine
S
Zayats
Tetyana
T
Owen
Michael J
MJ
Guggenheim
Jeremy A
JA
Young
Terri L
TL
D000328:Adult; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D024042:Collagen Type I / Q000235:genetics*; D000090602:Collagen Type I, alpha 1 Chain; D024043:Collagen Type II / Q000235:genetics*; D005260:Female; D008040:Genetic Linkage; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D009216:Myopia / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide
C499177:COL2A1 protein, human; D024042:Collagen Type I; D000090602:Collagen Type I, alpha 1 Chain; D024043:Collagen Type II; D005819:Genetic Markers