In silico analysis of SLC3A1 and SLC7A9 mutations in Iranian patients with Cystinuria

Cystinuria is an autosomal recessive defect in reabsorptive transport of cystine and the dibasic amino acids ornithine, arginine, and lysine from renal tubule and small intestine. Mutations in two genes: SLC3A1, encoding the heavy chain rbAT of the renal cystine transport system and SLC7A9, the gene of its light chain b(0, +) AT have a crucial role in the diseases. In our previous studies from Iranian populations with Cystinuria totally six and eleven novel mutations respectively identified in SLC3A1 and SLC7A9 genes. In this study, we conducted an in silico functional analysis to explore the possible association between these genetic mutations and Cystinuria. MutationTaster, PolyPhen-2, PANTHER, FATHMM. PhDSNP and MutPred was applied to predict the degree of pathogenicity for the missense mutations. Furthermore, Residue Interaction Network (RIN) and Intron variant analyses was performed using Cytoscape and Human Slicing Finder softwares. These genetic variants can provide a better understanding of genotype-phenotype relationships in patients with Cystinuria. In the future, the findings may also facilitate the development of new molecular diagnostic markers for the diseases.