The natural history of Leber congenital amaurosis and cone–rod dystrophy associated with variants in the GUCY2D gene

Objective To describe the spectrum of Leber congenital amaurosis (LCA) and cone–rod dystrophy (CORD) associated with the GUCY2D gene and to identify potential end points and optimal patient selection for future therapeutic trials. Design International, multicenter, retrospective cohort study. Subjects Eighty-two patients with GUCY2D-associated LCA or CORD from 54 families. Methods Medical records were reviewed for medical history, best-corrected visual acuity (BCVA), ophthalmoscopy, visual fields, full-field electroretinography, and retinal imaging (fundus photography, spectral-domain OCT [SD-OCT], fundus autofluorescence). Main Outcomes Measures Age of onset, evolution of BCVA, genotype–phenotype correlations, anatomic characteristics on funduscopy, and multimodal imaging. Results Fourteen patients with autosomal recessive LCA and 68 with autosomal dominant CORD were included. The median follow-up times were 5.2 years (interquartile range [IQR] 2.6–8.8 years) for LCA and 7.2 years (IQR 2.2–14.2 years) for CORD. Generally, LCA presented in the first year of life. The BCVA in patients with LCA ranged from no light perception to 1.00 logarithm of the minimum angle of resolution (logMAR) and remained relatively stable during follow-up. Imaging for LCA was limited but showed little to no structural degeneration. In patients with CORD, progressive vision loss started around the second decade of life. The BCVA declined annually by 0.022 logMAR (P < 0.001) with no difference between patients with the c.2513G>A and the c.2512C>T GUCY2D variants (P = 0.798). At the age of 40 years, the probability of being blind or severely visually impaired was 32%. The integrity of the ellipsoid zone (EZ) and that of the external limiting membrane (ELM) on SD-OCT correlated significantly with BCVA (Spearman ρ = 0.744, P = 0.001, and ρ = 0.712, P < 0.001, respectively) in those with CORD. Conclusions Leber congenital amaurosis associated with GUCY2D caused severe congenital visual impairment with relatively intact macular ...