Female carrier of RPGR mutation presenting with high myopia

ABSTRACT

Background

Inherited retinopathies can initially present with high refractive error in the first decade of life, before accompanying signs or symptoms are evident.

Case presentation

A 4-year-old girl with high myopia (S-12.00 C-4.00 × 20 in the right and S-14.50 C-2.75 × 160 in the left eye), moderate visual acuity (0.3 logMAR in the right and 0.4 logMAR in the left eye), and left esotropia, presented with unremarkable past medical history and no family history of high refractive error or low vision. In optical coherence tomography imaging, macular thinning was evident, while morphology was normal. Full-field electroretinogram revealed normal implicit time recordings with reduced amplitudes in scotopic and photopic conditions. Fundus autofluorescence showed a radial pattern in both eyes. During a 5-year follow-up, significant myopia progression ensued (S-17.25 C-3.00 × 20 in the right and S-17.25 C-2.00 × 160 in the left eye), with a corresponding increase in axial length and an unchanged visual acuity. Whole-exome sequencing revealed a heterozygous termination codon variant c.212C>G (p.Ser71Ter) in RPGR, considered to be pathogenic. Segregation analysis precluded the variation in the mother and sister. A random pattern of X-chromosome inactivation was detected in the proband, without X-chromosome inactivation deviation.

Conclusion

This is the second report associating this specific RPGR mutation with high myopia and the first report to identify it in a female proband. This case provides additional evidence on the genotypic-phenotypic correlation between RPGR c.212C>G mutation and high myopia.

KEYWORDS:

• High myopia
• retinitis pigmentosa
• mutation
• termination codon variant
• RPGR
• XLRP
• female carriers
• retinitis pigmentosa GTPase regulator

Disclosure statement

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

Consent for publication

Written informed consent was obtained from the parents for publication of this case report.

Additional information

Funding

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