PRPS1-associated retinopathy: a diagnostic odyssey

ABSTRACT

Purpose

This study describes how the diagnosis of Usher syndrome was revised to PRPS1-associated retinopathy and Charcot—Marie—Tooth disease type 5.

Case Report

A 38-year-old female with bilaterally subnormal vision and non-congenital hearing loss was initially diagnosed with Usher syndrome, based on finding variants in three genes (MYO7A, USH2A, and PCDH15), was re-evaluated at the inherited retinal disorders clinic. She had asymmetric retinopathy and right macular pseudocoloboma. She was also found to have myopathic facies, poor grip strength and atrophy of the calf muscles. Whole exome sequencing including variants in PRPS1 showed a variant (NM_002764.4:c.287 G > A; p.Arg96Gln), which was not detected by targeted Sanger sequencing of the DNA from her mother and sister.

Conclusion

The constellation of asymmetric retinopathy and non-congenital hearing impairment should prompt the clinician to search for other diagnoses that may not be covered by an Usher syndrome next generation sequencing panel. Interpretation of genetic testing results should be correlated with a detailed clinical phenotype.

KEYWORDS:

• PRPS1
• retinopathy
• macular coloboma
• pseudocoloboma
• sensorineural hearing loss
• Usher syndrome
• Charcot–Marie–Tooth
• inherited retinal disease

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.

Additional information

Funding

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