Is RPGR-related retinal dystrophy associated with systemic disease? A case series

ABSTRACT

Background

Ciliopathies responsible for retinitis pigmentosa can also cause systemic manifestations. RPGR is a ciliary gene and pathogenic variants in RPGR cause a retinal ciliopathy, the commonest cause of X-linked recessive retinitis pigmentosa. The RPGR protein interacts with numerous other ciliary proteins present in the transition zone of both motile and sensory cilia, and may play an important role in regulating ciliary protein transport. There has been a growing, putative association of RPGR variants with systemic ciliopathies: mainly sino-respiratory infections and primary ciliary dyskinesia.

Materials and Methods

Retrospective case series of patients with RPGR-RP presenting to Oxford Eye Hospital with systemic disease.

Results

We report three children with RPGR-related rod-cone dystrophy, all of whom have mutations in the N-terminus of RPGR. Two cases co-presented with confirmed diagnoses of primary ciliary dyskinesia and one case with multiple sino-respiratory symptoms strongly suggestive of primary ciliary dyskinesia. These and all previously reported RPGR co-pathologies relate to ciliopathies and have no other systemic associations.

Conclusions

The link between RPGR variants and a systemic ciliopathy remains plausible, but currently unproven.

KEYWORDS:

• RPGR
• retinitis pigmentosa
• primary ciliary dyskinesia
• ciliopathy

Acknowledgements

With many thanks to Claire Hogg of the Royal Brompton for her comments and expert advice on the text.

Disclosure statement

Robert E MacLaren is listed as an inventor on a patent for RPGR gene therapy owned by the University of Oxford.

Notes

¹ Of note, this patient has been reported in Carss et al (30) associated with a Congenital Stationary Night Blindness (CSNB) phenotype: the authors have identified that this appears to be a transcription error in the patient’s original recruitment documents, perhaps due to a misinterpretation of “night blindness” as a symptom into “CSNB.”

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.