Identification and replication of three novel myopia common susceptibility gene loci on chromosome 3q26 using linkage and linkage disequilibrium mapping.
Refractive error is a highly heritable quantitative trait responsible for considerable morbidity. Following an initial genome-wide linkage study using microsatellite markers, we confirmed evidence for linkage to chromosome 3q26 and then conducted fine-scale association mapping using high-resolution linkage disequilibrium unit (LDU) maps. We used a preliminary discovery marker set across the 30-Mb region with an average SNP density of 1 SNP/15 kb (Map 1). Map 1 was divided into 51 LDU windows and additional SNPs were genotyped for six regions (Map 2) that showed preliminary evidence of multi-marker association using composite likelihood. A total of 575 cases and controls selected from the tails of the trait distribution were genotyped for the discovery sample. Malecot model estimates indicate three loci with putative common functional variants centred on MFN1 (180,566 kb; 95% confidence interval 180,505-180, 655 kb), approximately 156 kb upstream from alternate-splicing SOX2OT (182,595 kb; 95% CI 182,533-182,688 kb) and PSARL (184,386 kb; 95% CI 184,356-184,411 kb), with the loci showing modest to strong evidence of association for the Map 2 discovery samples (p<10(-7), p<10(-10), and p = 0.01, respectively). Using an unselected independent sample of 1,430 individuals, results replicated for the MFN1 (p = 0.006), SOX2OT (p = 0.0002), and PSARL (p = 0.0005) gene regions. MFN1 and PSARL both interact with OPA1 to regulate mitochondrial fusion and the inhibition of mitochondrial-led apoptosis, respectively. That two mitochondrial regulatory processes in the retina are implicated in the aetiology of myopia is surprising and is likely to provide novel insight into the molecular genetic basis of common myopia.
Twin Research and Genetic Epidemiology, King's College London, St Thomas' Hospital, London, UK. toby.andrew@kcl.ac.uk
Toby
T
Andrew
Nikolas
N
Maniatis
Francis
F
Carbonaro
S H Melissa
SH
Liew
Winston
W
Lau
Tim D
TD
Spector
Christopher J
CJ
Hammond
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D002874:Chromosome Mapping; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics; D004200:Diseases in Twins / Q000235:genetics; D005260:Female; D020558:GTP Phosphohydrolases / Q000235:genetics; D020022:Genetic Predisposition to Disease; D024002:HMGB Proteins / Q000235:genetics; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics; D008875:Middle Aged; D033681:Mitochondrial Membrane Transport Proteins; D024101:Mitochondrial Proteins / Q000235:genetics; D009216:Myopia / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D053763:Presenilins / Q000235:genetics; D055748:SOXB1 Transcription Factors; D014157:Transcription Factors / Q000235:genetics
D004268:DNA-Binding Proteins; D024002:HMGB Proteins; D026901:Membrane Transport Proteins; D033681:Mitochondrial Membrane Transport Proteins; D024101:Mitochondrial Proteins; D053763:Presenilins; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors; D014157:Transcription Factors; D020558:GTP Phosphohydrolases; C415198:OPA1 protein, human; C470017:Mfn1 protein, human