Early onset primary angle closure and foveal retinoschisis associated with a pseudo-homozygous CRB1 pathogenic variant.

PURPOSE: We describe a case of a 4-year-old Chinese girl who presented with elevated intraocular pressure (IOP), and foveal retinoschisis (FRS) in both eyes, which was later diagnosed as CRB1-associated retinopathy.

METHODS AND

RESULTS

Ultrasound biomicroscopy demonstrated shallow anterior chamber, angle closure, anterior insertion of iris and anteriorly positioned ciliary body. The patient received laser peripheral iridotomy and topical medications for ocular hypertension and macular oedema. Longitudinal follow-up over 2 years revealed improved visual acuity, and effective IOP control. However, the FRS continued to progress. Genetic screening confirmed a novel copy number loss and a pseudo-homozygous c.4207G > C (p.Glu1403Gln) variant of the CRB1 gene.

CONCLUSIONS

This case underscores the importance of comprehensive ophthalmologic examination and genetic testing in young patients with primary angle closure. In addition, the patient's hemizygous state for the CRB1 gene provides a unique opportunity to establish a genotype-phenotype association between the c.4207G > C (p.Glu1403Gln) variant and maculopathy as well as elevated IOP.