The Correlation Between Lumican, Decorin Gene And Simple Pathological Myopia

Objective: Pathological myopia(PM) is a kind of ametropia that diopter is more than -6.0D, usually accompanying lengthening of ocular axis and changing of ocular fundus such as temperal crescent, pigment epithelium thinning, leopard retina, Fuch's macula, retina-choroidal atrophy and so on, with continuous eyesight's deterioration. PM can cause many complications including amblyopia, glaucoma, cataract, vitreous opacification, Detachment of retina etc, and become a kind of severe hereditary ocular disease that can lead to blinding. Domestic and overseas researches have confirmed PM's heritage and genetic heterogeneity. Up to now we know 9 affirmative gene locus, including Xq28(MYP1), 18p11.31(MYP2), 12q21-q23(MYP3), 7q36(MYP4), 17q21-q22 (MYP5), 4q22-q27, 2q37.1, Xq23-q25, 15q12–13. In MYP3, Lumican(LUM)and Decorin(DCN) gene is two important candidate genes, and express protein parts of proteoglycans in extracellular matrix(ECM). Proteoglycans can affect fibre's growth and is closedly related to sclerotic growth and function. This research's purpose is to analyze sequences of the exon2, 5'-regulatory region around the single nucleotide polymorphism (SNP) of rs3759223 in the lumican (LUM) gene and the exon7 of Decorin (DCN) gene in individuals with Simple PM and control subjects, and then investigate the relationship between LUM, DCN gene and pathological myopia.Methods: 29 individuals with Simple PM (including 8 individuals in a family and 21 sporadic patients) were selected and 15 males and 14 females were included. And 31 control subjects were selected (16 males, 15 females). Genomic DNA was collected from 5ml vein blood, and then the exon2, 5'-regulatory region around rs3759223 in the LUM gene and the exon7 of DCN gene were analyzed by polymerase chain reaction (PCR) and direct sequencing. The relationship between LUM, DCN gene and pathological myopia was analysed with statistics.Results: 4 sequence variants in PM individuals were identified: 507T→C(synonymous mutation, N169N) in the exon2 of LUM gene; 3 base substitutions around rs3759223: -3892A→T, -3889G→T and -3888C→A.Incidence rate of the first mutation was 51.72% (15/29) in PM individuals, and 12.90% (4/31) in control subjects. And incidence rate of latter three mutations was 63.16% (12/29) in PM individuals, and 6.45% (2/31) in control subjects. The correlation between rs3759223 and PM that was once reported, wasn't authenticated again in this research. No mutation was identified in the exon7 of DCN gene.Conclusion: As a important candidate gene in MYP3(12q21-q23), the sequence variants in 5'-regulatory region of LUM gene are associated significantly with PM. However, Further studies are needed to confirm finally whether LUM is the virulence gene of PM, and how mutation in LUM gene acts in the developement of PM and whether DCN gene is related to PM.