RTN4IP1-associated non-syndromic optic neuropathy and rod-cone dystrophy

ABSTRACT

Background

Biallelic variants in RTN4IP1 are a well-established cause of syndromic and nonsyndromic early-onset autosomal recessive optic neuropathy. They have more recently been reported to cause a concomitant but later-onset rod-cone dystrophy with or without syndromic features.

Methods

A comprehensive evaluation was performed that included assessment of visual and retinal function, clinical examination, and retinal imaging. Childhood ophthalmic records as well as the results of genetic testing were evaluated.

Results

A 24-year-old female described longstanding reduced visual acuity with more recent subjective impairment of dark adaptation. Visual acuity was subnormal in both eyes. Goldmann kinetic perimetry demonstrated scotomas in a pattern consistent with the presence of both optic neuropathy and rod-cone dystrophy with fundus exam as well as retinal imaging showing corroborating findings. Full-field electroretinography further confirmed the presence of a rod-cone dystrophy. Genetic testing demonstrated biallelic variants in RTN4IP1, one of which was novel, in association with the ocular findings.

Conclusions

RTN4IP1-associated early-onset bilateral optic neuropathy with rod-cone dystrophy is a recently described clinical entity with limited reports available to-date. The present case provides additional support for this dual phenotype and identifies a novel causative variant.

KEYWORDS:

• RTN4IP1
• reticulon 4 interacting protein 1
• mitochondrial retinal dystrophy
• rod-cone dystrophy
• hereditary optic neuropathy

Disclosure statement

No potential conflict of interest was reported by the author(s).

Approvals

Written consent to publish was obtained from the individual described in this report.

Additional information

Funding

This work was supported by the Foundation Fighting Blindness under a Clinical Research Fellowship Award (PG) and a Career Development Award (RH; CD-CMM-0918-0747-MEEI).