title: Genomewide linkage scans for ocular refraction and meta-analysis of four populations in the Myopia Family Study.
abstract: OBJECTIVE
  Genomewide linkage scans were performed in Caucasian (CAUC) and Old Order Amish (OOA) families to identify genomic regions containing genes responsible for refractive error control. We also performed a meta-analysis by combining these results with our previous linkage results from Ashkenazi Jewish (ASHK) and African American (AFRAM) families.
  
  
  METHODS
  Two hundred seventy-one CAUC and 411 OOA participants (36 and 61 families, respectively) were recruited to participate in the Myopia Family Study. Recruitment criteria were designed to enrich the sample for multiplex myopic families. Genomewide, model-free, multipoint linkage analyses were performed separately for each population by using >370 microsatellite markers. Empirical significance levels were determined via gene-dropping simulations. A meta-analysis was performed by combining linkage results from the CAUC, OOA, AFRAM, and ASHK samples, and results were compared to previously reported loci for myopia and refraction.
  
  
  RESULTS
  Suggestive evidence of linkage was found at 12q24 (LOD = 4.583, P = 0.00037) and 4q21 (LOD = 2.72, P = 0.0028) in the CAUC sample and at 5qter (LOD = 3.271, P = 0.0014) in the OOA. Meta-analysis linkage results were largely driven by population-specific signals from ASHK and AFRAM families. The meta-analysis showed suggestive evidence of linkage to 4q21-22 (meta-P = 0.00214) adjacent to the previously reported MYP9 and MYP11 loci.
  
  
  CONCLUSIONS
  The results showed suggestive evidence of linkage of ocular refraction to 12q24 and 4q21 in CAUC and to 5qter in OOA families. The meta-analysis supports the view that several genes play a role in refractive development across populations. In MFS families, four broad genomic regions (on 1p, 4q, 7p, and 12q) most likely contain genes that influence ocular refraction.
authors.affiliation: Inherited Disease Research Branch, National Human Genome Research Institute, Baltimore, Maryland 21231, USA. robwoj@mail.nih.gov
authors.forename: Robert
authors.initials: R
authors.lastname: Wojciechowski
authors.forename: Dwight
authors.initials: D
authors.lastname: Stambolian
authors.forename: Elise
authors.initials: E
authors.lastname: Ciner
authors.forename: Grace
authors.initials: G
authors.lastname: Ibay
authors.forename: Taura N
authors.initials: TN
authors.lastname: Holmes
authors.forename: Joan E
authors.initials: JE
authors.lastname: Bailey-Wilson
mesh_terms: D000328:Adult; D044383:Black People / Q000235:genetics; D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics*; D005260:Female; D008040:Genetic Linkage; D015894:Genome, Human; D005838:Genotype; D006801:Humans; D007585:Jews / Q000235:genetics; D008126:Lod Score; D008297:Male; D009216:Myopia / Q000235:genetics*; D040641:Quantitative Trait Loci; D012029:Refraction, Ocular / Q000235:genetics*; D044465:White People / Q000235:genetics; D001741:Black or African American