Association of insulin-like growth factor-1 polymorphisms with high myopia in the Chinese population

Abstract

Purpose: The purpose of this study was to determine whether genetic variants in the insulin-like growth factor-1 (IGF-1) gene were associated with high myopia in the Chinese population.

Methods: A case-control association study of 421 unrelated Chinese patients with high myopia and 401 control subjects matched in ethnicity and gender was undertaken. Genomic DNA was prepared from peripheral blood. All individuals were genotyped for 7 tag single nucleotide polymorphisms (tSNPs) across the IGF-1 gene region. Genotypic distribution was tested for Hardy-Weinberg equilibrium. The genotype and allele frequencies were evaluated using the χ(2) tests. Bonferroni corrections for multiple comparisons were performed.

Results: The polymorphism of rs12423791 showed positive association with extreme myopia (p(allel)=0.006 and p(allel1 recessive model)=0.004, respectively) after Bonferroni correction for multiple testing and the haplotype GC of rs5742629-rs12423791 was also associated with extreme myopia (p=0.033) after 50,000 permutations for multiple comparisons.

Conclusions: The polymorphism of rs12423791 in IGF-1 may be associated with extreme myopia in the Chinese population and should be investigated further.

Figure 1

Three haplotype blocks of 7 tag SNPs of the IGF-1 gene. Seven tag SNPs for IGF-1 are shown in relation to the three haplotype blocks in HapMap CHB population, which were determined by the Haploview 4.2 program and the HapMap database. Darker shades represented stronger linkage disequilibrium.