DO: 11830;
Cytogenetic location: 11p13 Genomic coordinates (GRCh38): 11:31,000,001-36,400,000
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
|---|---|---|---|---|
| 11p13 | Myopia 7 | 609256 | Multifactorial | 2 |
Myopia, or nearsightedness, is a refractive error of the eye. Light rays from a distant object are focused in front of the retina and those from a near object are focused in the retina; therefore distant objects are blurry and near objects are clear (summary by Kaiser et al., 2004).
For a discussion of genetic heterogeneity of susceptibility to myopia, see 160700.
Hammond et al. (2004) undertook a classic twin study of 506 twin pairs, 280 dizygotic (DZ) and 226 monozygotic (MZ), to establish the heritability of refractive error as determined by mean spherical equivalent (SE). The mean SE for the 506 twin pairs was +0.39 diopters (D), with a range of -12.12 D to +7.25 D. Only 4 MZ and 3 DZ twin pairs were well within the high myopia range (more than -6.00 D). The heritability of refractive error was inferred to be 0.89. To ascertain potential susceptibility loci for myopia, Hammond et al. (2004) performed a genomewide linkage scan for the continuous trait using 221 of the DZ twin pairs. Maximum evidence for linkage was observed at chromosome 11p13 (MYP7), with a lod score of 6.1. Other linkage peaks were observed at chromosomes 3q26 (MYP8; 609257), 4q12 (MYP9; 609258), and 8p23 (MYP10; 609259), with lod scores of 3.7, 3.3, and 4.1, respectively. The most likely candidate gene on chromosome 11p13 was PAX6 (607108), which was directly beneath the highest linkage peak. However, Hammond et al. (2004) failed to find a phenotypic association with a common SNP in the PAX6 gene, and they suggested that further mapping is required to confirm whether linkage to PAX6 is due to regulatory loci or to linkage to an unrecognized nearby gene.
Hammond, C. J., Andrew, T., Mak, Y. T., Spector, T. D. A susceptibility locus for myopia in the normal population is linked to the PAX6 gene region on chromosome 11: a genomewide scan of dizygotic twins. Am. J. Hum. Genet. 75: 294-304, 2004. [PubMed: 15307048] [Full Text: https://doi.org/10.1086/423148]
Kaiser, P. K., Friedman, N. J., Pineda, R., II. The Massachusetts Eye and Ear Infirmary Illustrated Manual of Ophthalmology. Vol. 2. Philadelphia: Saunders , 2004. P. 457.