IMPG2-associated retinal dystrophy with a novel missense variant and therapeutic options via adenine base editing

We describe a novel missense variant in IMPG2 in a patient with early-onset rod-cone dystrophy with central macular atrophy and evaluate the potential of adenine base editing (ABE) as a therapeutic strategy. Ophthalmic evaluation included ultra-widefield fundus photography, fundus autofluorescence, and spectral-domain optical coherence tomography. Genetic testing was performed with a targeted next-generation sequencing panel and Sanger confirmation. Variant pathogenicity was assessed using in silico prediction tools, protein stability algorithms, and structural modeling. ABE feasibility was analyzed through PAM site identification and guide RNA design. Genetic testing revealed compound heterozygosity for a pathogenic nonsense variant (c.411G>A; p.Trp137*) and a novel missense variant (c.871C>A; p.Arg291Ser) within the SEA-1 domain. While in silico prediction tools classified p.Arg291Ser as benign or neutral, structural modeling and stability analyses supported a destabilizing effect. Base editing assessment indicated that c.411G>A is targetable with ABE. This case underscores the clinical relevance of domain-specific IMPG2 variants and the limitations of in silico predictions. ABE offers a promising therapeutic option for IMPG2-associated retinopathy.