Identification Of P4HA2Mutations In High Myopia Using Exome Sequencing

Background:Myopia, which can be accompanied with the clinical characteristics of degeneration of retinal atrophy, retinal detachment, macular bleeding, even blindness, is a condition of refractive error in the eye characterized by the focal point of parallel light rays being in front of the fovea, resulting in blurred vision. Myopia could severely impact the visual health and life qualities of patients, ranking the6th of the visual disorders leading to blindness.High myopia whole genome scan and genetic linkage analysis have already done in diverse nations and areas. Reported loci includes but not limited to:1p36,2q37.1,3q26,4q12. Reported genes which associated with high myopia include:SCO2, LEPREL1, ZNF644, SLC39A5etc.Aim:To identify the disease causative gene of High Myopia.Method:HM-SR3-2high myopia pedigree, including9patients with myopia and3normal people, were recruited from Zhuzhou, diagnosed by2physicians from the2nd Xiangya Hospital. According to the results of exomes sequence, sanger sequence were applied to identified the causative gene. QPCR and Western blotting were applied to detect the expression of the gene.Results:c.871G>A heterozygous mutations of P4HA2is identified co-separated in the pedigree, which is absent in209normal controls. More mutations heterozygous mutations of P4HA2including c.448A>G, c.419A>G, c.1349-1350GTdel, c.1327A>T, are discovered in sporadic cases and are absent in300controls. QPCR results indicate that P4HA2mRNA expressed lower in patients, however, the phenomenon is rescued after treating with Emetine. The result of western blotting also shows a decline in P4HA2protein expression.Conclusion:c.871G>A heterozygous mutations of P4HA2is identified co-separated in the pedigree and this mutation leads to p.291E>K, which is absent in controls; c.448A>G, c.419A>G, c.1349-1350delGT, c.1327A>T are identified in sporadic casese which are all absent in300controls; P4HA2mRNA in patients degenerated earlie; P4HA2protein expressed lower in patients; P4HA2might be the disease causative gene of high myopia.