Lack of association with high myopia and the MYP2 locus in the Japanese population by high resolution microsatellite analysis on chromosome 18

Takahiro Yamane¹, Jeewon Mok², Akira Oka², Eiichi Okada³, Ritsuko Nishizaki^1,3, Akira Meguro¹, Junichi Yonemoto¹, Jerzy K Kulski^2,4, Shigeaki Ohno⁵, Hidetoshi Inoko², Nobuhisa Mizuki¹

¹Department of Ophthalmology, Yokohama City University School of Medicine, Yokohama, Kanagawa, Japan; ²Department of Basic Medical Science and Molecular Medicine, Tokai University School of Medicine, Isehara, Kanagawa, Japan; ³Okada Eye Clinic, Yokohama, Kanagawa, Japan; ⁴Centre for Comparative Genomics, School for Information Technology, Murdoch University, Murdoch, Western Australia, Australia; ⁵Department of Ophthalmology, Hokkaido University School of Medicine, Sapporo, Hokkaido, Japan

Abstract: MYP2 was reported for a candidate locus associated with high grade myopia by linkage analysis, but no candidate gene has been detected. We report an association study in the Japanese population using 750 microsatellite markers on chromosome 18 that include MYP2 locus. 450 Japanese subjects with high myopia whose refractive error was greater than or equal to –9.25D in at least one eye and equal number of normal control subjects were recruited in this study. Three steps screening on the pooled DNA of patients and the pooled DNA of controls were performed in this study. A total of 722 microsatellite markers could be analyzed, and we obtained 4 positive markers. Then to avoid experimental errors and artifacts, we confirmed true allele frequency by individual genotyping using initial set of 450 patients and controls. Only marker D18S0301i showed statistically significance, and no marker showed statistically significance on the MYP2 locus. Near the marker D18S0301i, GALNT1 gene was located, but its relation to high myopia has remained to be identified.

Keywords: myopia, MYP2, microsatellite mapping, chromosome 18