Early-Onset X-Linked Retinitis Pigmentosa in a Heterozygous Female Harboring an Intronic Donor Splice Site Mutation in the Retinitis Pigmentosa GTPase Regulator Gene

Abstract

Purpose: To report a heterozygous female presenting with an early-onset and severe form of X-linked retinitis pigmentosa (XLRP).

Patients and Methods: This is a case series presenting the clinical findings in a heterozygous female with XLRP and two of her family members. Fundus photography, fundus autofluorescence, ocular coherence tomography, and visual perimetry are presented.

Results: The proband reported here is a heterozygous female who presented at the age of 8 years with an early onset and aggressive form of XLRP. The patient belongs to a four-generation family with a total of three affected females and four affected males. The patient was initially diagnosed with retinitis pigmentosa (RP) at the age of 4 years. Genetic testing identified a heterozygous donor splice site mutation in intron 1 (IVS1 + 1G > A) of the retinitis pigmentosa GTPase regulator gene. The father of the proband was diagnosed with RP when he was a young child. The sister of the proband, evaluated at the age of 6 years, showed macular pigmentary changes.

Conclusions: Although carriers of XLRP are usually asymptomatic or have a mild disease of late onset, the proband presented here exhibited an early-onset, aggressive form of the disease. It is not clear why some carrier females manifest a severe phenotype. A better understanding of the genetic processes involved in the penetrance and expressivity of XLRP in heterozygous females could assist in providing the appropriate counseling to affected families.

• Manifesting carrier
• retinitis pigmentosa
• retinitis pigmentosa GTPase regulator
• X-linked retinitis pigmentosa

Acknowledgments

We thank the family of the proband for their cooperation during the gathering of the information used in preparing this manuscript and for giving consent for the publication of their case reports. We acknowledge the support of Angela Hardin in the acquisition of the clinical data from the patients reported here.

Declaration of interest

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