title: Anophthalmia-esophageal atresia syndrome caused by an SOX2 gene deletion in monozygotic twin brothers with markedly discordant phenotypes.
abstract: The clinical combination of anophthalmia/microphthalmia and esophageal atresia was first recognized in 1988 as a distinct variable multi-system malformation syndrome and since then at least 17 cases of the disease have been described, all of them sporadic in occurrence. We report a heterozygous SOX2 gene mutation underlying the syndrome of anophthalmia/microphthalmia-esophageal atresia and demonstrate that this entity can be associated to considerable clinical variability as shown by the discordant ocular phenotype observed in monozygotic twin brothers carrying an SOX2 deletion. This is the first report describing a strikingly discordant eye phenotype in monozygotic twins with the condition, with one of our patients being the first reported individual carrying an SOX2 lesion associated with unilateral eye defect. We discuss the probable sources for this remarkable phenotypic heterogeneity of the anophthalmia/microphthalmia syndrome in individuals with an identical genetic constitution.
authors.affiliation: Department of Genetics, Institute of Ophthalmology "Conde de Valenciana," Mexico City, Mexico. jczenteno@salud.gob.mx
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Zenteno
authors.forename: Hector J
authors.initials: HJ
authors.lastname: Perez-Cano
authors.forename: Monica
authors.initials: M
authors.lastname: Aguinaga
mesh_terms: D000853:Anophthalmos / Q000175:diagnosis* / Q000235:genetics*; D004933:Esophageal Atresia / Q000175:diagnosis* / Q000235:genetics*; D017353:Gene Deletion; D024002:HMGB Proteins / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D010641:Phenotype; D055748:SOXB1 Transcription Factors; D013577:Syndrome; D014157:Transcription Factors / Q000235:genetics*; D014430:Twins, Monozygotic
chemical_list: D024002:HMGB Proteins; C527782:SOX2 protein, human; D055748:SOXB1 Transcription Factors; D014157:Transcription Factors