The role of Frizzled-4 mutations in familial exudative vitreoretinopathy and Coats disease.

AIM: The aim of this study is to assess the role of Frizzled-4 (FZD4) in familial exudative vitreoretinopathy (FEVR) and Coats disease. METHODS: Tissue samples were collected for DNA extraction and automated DNA sequencing of the two coding exons of FZD4 in both directions. Cases carrying a FZD4 mutation and demonstrating extreme disease severity were selected for direct automated sequencing of all coding exons of LRP5, NDP and TSPAN12. Clinical data were obtained for the purpose of identifying genotype-phenotype correlations. RESULTS: 68 probands were diagnosed as having autosomal dominant or sporadic FEVR. Eleven FZD4 mutations (five missense, three deletions, one insertion, two nonsense) were identified. Six of these mutations are novel, and none were found in 346 control chromosomes. In 16 cases of Coats disease, one polymorphism combination was found in two samples: no mutations were detected. No genotype-phenotype correlation emerged. Three severely affected cases with FZD4 mutations failed to show additional mutations in the three other FEVR genes. CONCLUSION: The authors identified 12 FEVR probands with FZD4 mutations. FZD4 mutation screening can be a useful tool especially in mild or atypical cases of FEVR. Germ-line mutations in FZD4 do not appear to be a common cause of Coats disease.

Instability of ocular alignment in childhood esotropia.

OBJECTIVE: Instability of ocular alignment may cause surgeons to delay surgical correction of childhood esotropia. The authors investigated the stability of ocular alignment over 18 weeks in children with infantile esotropia (IET), acquired nonaccommodative esotropia (ANAET), or acquired partially accommodative esotropia (APAET). DESIGN: Prospective, observational study. PARTICIPANTS: Two hundred thirty-three children aged 2 months to less than 5 years with IET, ANAET, or APAET of less than 6 months' duration. METHODS: Ocular alignment was measured at baseline and at 6-week intervals for 18 weeks. MAIN OUTCOME MEASURES: Using definitions derived from a nested test-retest study and computer simulation modeling, ocular alignment was classified as unstable if there was a change of 15 prism diopters (PD) or more between any 2 of the 4 measurements, as stable if all 4 measurements were within 5 PD or less of one another, or as uncertain if neither criteria was met. RESULTS: Of those who completed all 3 follow-up visits within time windows for analysis, 27 (46%) of 59 subjects with IET had ocular alignment classified as unstable (95% confidence interval [CI], 33%-59%), 20% as stable (95% CI, 11%-33%), and 34% as uncertain (95% CI, 22%-47%). Thirteen (22%) of 60 subjects with ANAET had ocular alignment classified as unstable (95% CI, 12%-34%), 37% as stable (95% CI, 25%-50%), and 42% as uncertain (95% CI, 29%-55%). Six (15%) of 41 subjects with APAET had ocular alignment classified as unstable (95% CI, 6%-29%), 39% as stable (95% CI, 24%-56%), and 46% as uncertain (95% CI, 31%-63%). For IET, subjects who were older at presentation were less likely to have unstable angles than subjects who were younger at presentation (risk ratio for unstable vs stable per additional month of age, 0.85; 99% CI, 0.74-0.99). CONCLUSIONS: Ocular alignment instability is common in children with IET, ANAET, and APAET. The impact of this finding on the optimal timing for strabismus surgery in childhood esotropia awaits further study. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.