title: Genetic dissection of myopia: evidence for linkage of ocular axial length to chromosome 5q.
abstract: OBJECTIVE
  To estimate heritability and locate quantitative trait loci influencing axial length.
  
  
  METHODS
  Classic twin study of monozygotic and dizygotic twins reared together.
  
  
  METHODS
  Eight hundred ninety-three individuals from 460 families were recruited through the Twin Eye Study in Tasmania and the Brisbane Adolescent Twin Study (BATS) and had ocular axial length measured.
  
  
  METHODS
  Structural equation modeling on the entire sample was used to estimate genetic and environmental components of variation in axial length. Analysis of existing microsatellite marker genomewide linkage scan data was performed on 318 individuals from 142 BATS families.
  
  
  METHODS
  Ocular axial length.
  
  
  RESULTS
  The heritability estimate for axial length, adjusted for age and sex, in the full sample was 0.81. The highest multipoint logarithm of the odds (LOD) score observed was 3.40 (genomewide P = 0.0004), on chromosome 5q (at 98 centimorgans [cM]). Additional regions with suggestive multipoint LOD scores were also identified on chromosome 6 (LOD scores, 2.13 at 76 cM and 2.05 at 83 cM), chromosome 10 (LOD score, 2.03 at 131 cM), and chromosome 14 (LOD score, 2.84 at 97 cM).
  
  
  CONCLUSIONS
  Axial length, a major endophenotype for refractive error, is highly heritable and is likely to be influenced by one or more genes on the long arm of chromosome 5.
authors.affiliation: Genetic Epidemiology Unit, Queensland Institute of Medical Research, Brisbane, Australia. D.Mackey@utas.edu.au
authors.forename: Gu
authors.initials: G
authors.lastname: Zhu
authors.forename: Alex W
authors.initials: AW
authors.lastname: Hewitt
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Ruddle
authors.forename: Lisa S
authors.initials: LS
authors.lastname: Kearns
authors.forename: Shayne A
authors.initials: SA
authors.lastname: Brown
authors.forename: Jane R
authors.initials: JR
authors.lastname: Mackinnon
authors.forename: Christine Y
authors.initials: CY
authors.lastname: Chen
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hammond
authors.forename: Jamie E
authors.initials: JE
authors.lastname: Craig
authors.forename: Grant W
authors.initials: GW
authors.lastname: Montgomery
authors.forename: Nicholas G
authors.initials: NG
authors.lastname: Martin
authors.forename: David A
authors.initials: DA
authors.lastname: Mackey
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D002895:Chromosomes, Human, Pair 5 / Q000235:genetics*; D004200:Diseases in Twins / Q000235:genetics*; D005123:Eye / Q000473:pathology*; D005260:Female; D008040:Genetic Linkage; D005838:Genotype; D006801:Humans; D008126:Lod Score; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009216:Myopia / Q000235:genetics*; D040641:Quantitative Trait Loci; D019655:Quantitative Trait, Heritable; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic