Document Type : Review
Authors
1
Clinical Research Development Unit, Ghaem Hospital, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
2
Countess of Chester Hospital, Chester, UK
3
Department of Medical Laboratory Sciences, Khomein University of Medical Sciences, Khomein, Iran.
4
Student Research Committee, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
5
Department of Neurology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
6
Rare Pediatric Neurological Diseases Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
10.22038/rcm.2026.87714.1542
Abstract
Syndromic cone-rod dystrophies (CRDs) represent a heterogeneous group of genetic retinal disorders characterized by the progressive degeneration of photoreceptors. These conditions, through their impact on both cone and rod cells, lead to significant visual impairment, manifesting as diminished central visual acuity, compromised color perception, and increased light sensitivity. In addition to the associated ocular symptoms, syndromic CRDs are frequently seen accompanied with systemic manifestations, including that of skeletal, metabolic, neurological, renal, and cardiac anomalies, which complicate diagnosis and management. The genetic basis of syndromic CRDs is complex, involving several mutations in multiple genes linked to a diverse array of syndromic conditions, such as that of Bardet-Biedl, Usher, Alström, Jalili, Refsum disease, Senior-Loken, Cohen syndrome, Jeune, Sensenbrenner, and Joubert syndrome. Non-genetic assessments, such as that of electroretinography, play vital roles in differentiating CRDs, in particular syndromic forms, from pure cone dystrophies an, as they tend to reveal functional deficits in both cone and rod photoreceptors. This review aims to clarify the distinct genetic origins and clinical characteristics for these disorders.
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