Retained visual function in a subset of patients with long-chain 3-hydroxyacyl-CoA dehydrogenase deficiency (LCHADD).

Introduction

LCHADD causes retinopathy associated with low vision, visual field defects, nyctalopia and myopia. We report a retrospective long-term single-center study of 6 LCHADD patients trying to clarify if early diagnosis has an impact on the course and outcome of chorioretinal degeneration.

Methods

Long-term follow-up of visual acuity and staging of chorioretinal degeneration by fundus photography, optical coherence tomography (OCT) and autofluorescence (AF) in all six patients. Three patients (2 m/1 f; age 8-14.8 years) were diagnosed by newborn screening, a single patient early within the first year of life and treated promptly while the other two (1 m/1 f; age 23-24 years) were diagnosed later after developing symptoms. All carried HADHA variants; five were homozygous for the common p.E510Q variant, in one from the symptomatically diagnosed group p.[E510Q]; [R291*] was detected.

Results

All patients showed retinal alterations, but early diagnosis was associated with a milder phenotype and a longer preservation of visual function. Among symptomatic patients, only one showed mild retinal involvement at the time of diagnosis.

Conclusion

Despite the small number our study suggests that early diagnosis does not prevent retinopathy but might contribute to a milder phenotype with retained good visual acuity over time. OCT and AF are reliable non-invasive diagnostic tools to estimate the progression of early-stage retinal changes in LCHADD patients.