1- Student Research Committee, Golestan University of Medical Sciences, Gorgan, Iran
2- Gorgan Congenital Malformations Research Center, Jorjani Clinical Sciences Research Institute, Golestan University of Medical Sciences,Gorgan, Iran; Ischemic Disorders Research Center, Jorjani Clinical Sciences Research Institute, Golestan University of Medical Sciences, Gorgan, Iran ,oladnabidozin@yahoo.com
2- Gorgan Congenital Malformations Research Center, Jorjani Clinical Sciences Research Institute, Golestan University of Medical Sciences,Gorgan, Iran; Ischemic Disorders Research Center, Jorjani Clinical Sciences Research Institute, Golestan University of Medical Sciences, Gorgan, Iran ,
Abstract: (297 Views)
Background: Tay-Sachs disease (TSD) is a lysosomal storage disorder caused by the accumulation of GM2 gangliosides in neuronal tissues due to reduced or abolished β-hexosaminidase A activity. We conducted a comprehensive computational investigation to prioritize pathogenic missense variants in the HEXA gene and to elucidate their predicted structural and functional consequences through an integrated in silico workflow.
Methods: Complementary bioinformatic tools such as CADD, PolyPhen-2, SIFT, and REVEL were used to predict variant pathogenicity and functional impact. Protein stability was assessed using I‑Mutant and MUpro, while STRING, InterPro, and Evolutionary Trace were applied to investigate protein interactions, functional domains, and evolutionary conservation, respectively. Structural analyses were performed using PSIPRED, I-TASSER, ProtScale, and DynaMut2.
Results: Sequential prioritization identified 27 potentially pathogenic variants from an initial set of 124 missense variants. Among the known founder variants, p.Arg170Trp (R170W), frequently observed in the French-Canadian population, met all predefined prioritization criteria and was selected for detailed structural and functional evaluation. The analyses suggested that R170W preserves the overall protein architecture while potentially affecting β-hexosaminidase A function through decreased protein stability, altered molecular interactions, and subtle conformational changes.
Conclusion: Our comprehensive in silico structural and functional analyses provide a practical framework for prioritizing and interpreting pathogenic HEXA variants. The findings suggest that computationally prioritized variants may impair enzyme function through subtle effects on protein stability and structural dynamics while preserving the overall protein fold. This framework may support future efforts in molecular variant interpretation, genetic counseling, and carrier screening, particularly in populations with a high prevalence of Tay–Sachs disease. Further experimental validation is required to confirm these predictions.
Methods: Complementary bioinformatic tools such as CADD, PolyPhen-2, SIFT, and REVEL were used to predict variant pathogenicity and functional impact. Protein stability was assessed using I‑Mutant and MUpro, while STRING, InterPro, and Evolutionary Trace were applied to investigate protein interactions, functional domains, and evolutionary conservation, respectively. Structural analyses were performed using PSIPRED, I-TASSER, ProtScale, and DynaMut2.
Results: Sequential prioritization identified 27 potentially pathogenic variants from an initial set of 124 missense variants. Among the known founder variants, p.Arg170Trp (R170W), frequently observed in the French-Canadian population, met all predefined prioritization criteria and was selected for detailed structural and functional evaluation. The analyses suggested that R170W preserves the overall protein architecture while potentially affecting β-hexosaminidase A function through decreased protein stability, altered molecular interactions, and subtle conformational changes.
Conclusion: Our comprehensive in silico structural and functional analyses provide a practical framework for prioritizing and interpreting pathogenic HEXA variants. The findings suggest that computationally prioritized variants may impair enzyme function through subtle effects on protein stability and structural dynamics while preserving the overall protein fold. This framework may support future efforts in molecular variant interpretation, genetic counseling, and carrier screening, particularly in populations with a high prevalence of Tay–Sachs disease. Further experimental validation is required to confirm these predictions.
Keywords: Lysosomal Storage Diseases, Protein Stability, Tay-Sachs Disease, Missense Variants, In Silico Analysis
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