title: Chromosomes 4q28.3 and 7q31.2 as new susceptibility loci for comitant strabismus.
abstract: OBJECTIVE
  This study was designed to localize chromosomal susceptibility loci for comitant strabismus among Japanese families by genome-wide linkage analyses.
  
  
  METHODS
  Fifty-five Japanese families, with at least two members with comitant strabismus (esotropia and/or exotropia), were subject to full ophthalmic examination, careful ocular history, and review of medical records. DNA was obtained and genotyping was performed with PCR amplification of 400 microsatellite markers. Parametric and nonparametric linkage (NPL) analyses scores were calculated. Linkage analysis was performed for the whole set of families (55 families), and then a second analysis was performed for two subgroups with the phenotypes, esotropia and exotropia.
  
  
  RESULTS
  A multipoint parametric heterogeneity logarithm of the odds (HLOD) score of 3.62 was obtained at marker D4S1575 under a dominant model, with a NPL score of 2.68 (P=0.001). Testing under different penetrances and disease allele frequencies revealed two other susceptibility loci at 7q31.2 under a recessive model (HLOD scores=3.93 and 4.40 at 125.2 cM and 107.28 cM, respectively). Analysis of the subgroups revealed new susceptibility loci for esotropia; one locus at 8q24.21 is worthy of further investigation.
  
  
  CONCLUSIONS
  This study suggests multiple susceptibility loci for comitant strabismus. The loci at chromosomes 4q28.3 and 7q31.2 show a significant evidence of linkage.
authors.affiliation: Department of Ophthalmology, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama City, Japan.
authors.forename: Sherin
authors.initials: S
authors.lastname: Shaaban
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Matsuo
authors.forename: Hirotake
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Emi
authors.initials: E
authors.lastname: Itoshima
authors.forename: Takashi
authors.initials: T
authors.lastname: Furuse
authors.forename: Satoshi
authors.initials: S
authors.lastname: Hasebe
authors.forename: Qingrun
authors.initials: Q
authors.lastname: Zhang
authors.forename: Jurg
authors.initials: J
authors.lastname: Ott
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohtsuki
mesh_terms: D044466:Asian People / Q000235:genetics; D002874:Chromosome Mapping; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics*; D002897:Chromosomes, Human, Pair 7 / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D015894:Genome, Human; D005838:Genotype; D006801:Humans; D008126:Lod Score; D008297:Male; D008957:Models, Genetic; D010375:Pedigree; D013285:Strabismus / Q000235:genetics*