Novel mutation in a case of TTLL5-associated cone dystrophy with a characteristic ‘solar flare’ sign

Background/Purpose TTLL5-associated retinal dystrophy is a rare inherited retinopathy with a limited number of reported cases. We report a novel homozygous frameshift mutation in TTLL5 causing adult-onset cone-rod dystrophy, expanding the known clinical and mutational spectrum of this condition.Methods Retrospective case report utilizing multimodal longitudinal imaging, clinical examination, and molecular genetic testing in a single patient.Results A 49-year-old male presented with progressive visual decline over 4 years. Multimodal imaging demonstrated parafoveal ellipsoid zone loss consistent with a cone-rod dystrophy pattern. Genetic testing identified a novel homozygous TTLL5 frameshift mutation (c.2429del, p.Lys810Argfs*35) localized within the cofactor interaction domain.Conclusions This case expands the clinical spectrum of TTLL5-related retinopathies and underscores the utility of genetic testing and multimodal imaging in the diagnosis of inherited retinal diseases.