Supplementary Material for: GNB1-related rod-cone dystrophy: a case report

Introduction: The GNB1 (guanine nucleotide-binding protein, 1) gene encodes for the ubiquitous 1 subunit of heterotrimeric G proteins which are associated with G-protein-coupled receptors (GPCRs). GNB1 mutations cause a neurodevelopmental disorder characterized by a broad clinical spectrum. A novel variant has recently been confirmed in a case of rod-cone dystrophy. Case presentation: We describe the second confirmed case of a classical rod-cone dystrophy associated with a mutation located in exon 6 of GNB1 [NM_002074.5:c.217G>C, p.(Ala73Pro)] in a 56-year-old patient also presenting mild mental retardation, attention disorder, and truncal obesity. Conclusion: This paper confirms the role of GNB1 in the pathogenesis of a classic rod-cone dystrophy and highlights the importance of including this gene in the genetic analysis panel for inherited retinal diseases (IRDs).