Abstract
Purpose :
To report the proportion of retinal gene mutations and associated clinical and ancillary findings in a cohort of patients with visual complaints who were tested for anti-retinal antibodies
Methods :
We retrospectively reviewed patients seen in a university-based uveitis clinic from 2011-2018. Patients were included if differential diagnosis included autoimmune retinopathy (AIR) and antiretinal antibodies (ARA) were done. We evaluated clinical findings, retinal imaging, and electrophysiologic studies. Some patients were tested for retinal gene mutations. ARA and genetic testing were commercially available in the earlier years from Casey Eye Institute, Ocular Immunology and Molecular Diagnostics Laboratories, Portland OR. Later, genetic testing was performed by Molecular Vision, Hillsboro OR. Patients paid for ARA and genetic tests.
Results :
Of 35 patients who had positive ARA, 32 patients were tested for malignancy. Seven patients had malignancies and received a final diagnosis of paraneoplastic AIR. Two patients were diagnosed with vitamin A deficiency. Genotype testing for possible retinal degeneration was recommended in 19 patients and was performed in 8 patients. Two of 8 patients were homozygous for reported mutations in ABCA4 or NR2E3. Two patients were heterozygous for reported mutations in ABCA4 and one for a reported mutation in EYS. Heterozygosity for a likely pathogenic variant of MERTK occurred in one patient. There were probably damaging, heterozygous mutations in one patient each in IMPG2 and ABCA4 genes. One of the homozygous ABCA4 mutation patients was a 9 year old diagnosed with AIR after extensive evaluation elsewhere that included ARA; the diagnosis was changed to juvenile onset Stargardt disease. The 3 patients with heterozygous mutations in ABCA4 had better visual acuity and less outer retinal damage on OCT relative to other patients. No vascular leakage was detected on fluorescein angiography in any of the 8 patients with gene mutation (Table 1).
Conclusions :
Nearly half of patients with ARA in this study had plausible explanations for retinal dysfunction other than AIR, including paraneoplastic, nutritional and genetic causes. We recommend that panel testing for mutations in retinal genes be considered in selected patients suspected of AIR.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.