Relevance of Identifying JAG1 Mutations in Patients With Isolated Posterior Embryotoxon

PURPOSE: Although posterior embryotoxon (PE) has a high incidence in the general population, clinicians should exclude any sign of glaucoma in its presence. This anatomic abnormality is often referred to as "isolated" when the intraocular pressure is normal. Nevertheless, it may be the only sign of Alagille syndrome (AS) that can be clinically heterogenous, as presented here. This possibility must be known, to look for involvement of other organs, and in case of suspicion, mutation of the JAG1 gene must be considered. METHODS: In this case series, we present the observation of a family with 3 individuals from 3 generations, in whom PE was a marker of AS. RESULTS: PE were observed in these 3 patients and considered as "isolated" as the intraocular pressure was normal. The 2 elder patients were also followed for atypical retinal dystrophy with speckling of the retinal pigment and optic disc drusen. AS syndrome was suspected when mild liver dysfunction was detected in the youngest girl. The detection of JAG1 mutation confirmed this diagnosis. CONCLUSIONS: As AS can be clinically heterogenous, it must be considered in case of isolated PE. Involvement of other organs must be looked for to search for mutation of the JAG1 gene in relevant cases.