BACKGROUND: Single-nucleotide polymorphisms (SNPs) have a crucial function in affecting the susceptibility of individuals to diseases and also determine how an individual responds to different treatment options. The present study aimed to predict and characterize deleterious missense nonsynonymous SNPs (nsSNPs) of lysozyme C (LYZ C) gene using different computational methods. Lyz C is an important antimicrobial peptide capable of damaging the peptidoglycan layer of bacteria leading to osmotic shock and cell death. The nsSNPs were first analyzed by SIFT and PolyPhen v2 tools. The nsSNPs predicted as deleterious were then assessed by other in silico tools - SNAP, PROVEAN, PhD-SNP, and SNPs & GO. These SNPs were further examined by I-Mutant 3.0 and ConSurf. GeneMANIA and STRING tools were used to study the interaction network of the LYZ C gene. NetSurfP 2.0 was used to predict the secondary structure of Lyz C protein. The impact of variations on the structural characteristics of the protein was studied by HOPE analysis. The structures of wild type and variants were predicted by SWISS-MODEL web server, and energy minimization was carried out using XenoPlot software. TM-align tool was used to predict root-mean-square deviation (RMSD) and template modeling (TM) scores.
RESULTS: Eight missense nsSNPs (T88N, I74T, F75I, D67H, W82R, D85H, R80C, and R116S) were found to be potentially deleterious. I-Mutant 3.0 determined that the variants decreased the stability of the protein. ConSurf predicted rs121913547, rs121913549, and rs387906536 nsSNPs to be conserved. Interaction network tools showed that LYZ C protein interacted with lactoferrin (LTF). HOPE tool analyzed differences in physicochemical properties between wild type and variants. TM-align tool predicted the alignment score, and the protein folding was found to be identical. PyMOL was used to visualize the superimposition of variants over wild type.
CONCLUSIONS: This study ascertained the deleterious missense nsSNPs of the LYZ C gene and could be used in further experimental analysis. These high-risk nsSNPs could be used as molecular targets for diagnostic and therapeutic interventions.

BACKGROUND: Lynch syndrome is the most common genetic predisposition for hereditary cancer. Carriers of pathogenic changes in mismatch repair (MMR) genes have an increased risk of developing colorectal (CRC), endometrial, ovarian, urinary tract, prostate, and other cancers, depending on which gene is malfunctioning. In Lynch syndrome, differences in cancer incidence (penetrance) according to the gene involved have led to the stratification of cancer surveillance. By contrast, any differences in penetrance determined by the type of pathogenic variant remain unknown.
OBJECTIVE: To determine cumulative incidences of cancer in carriers of truncating and missense or aberrant splicing pathogenic variants of the MLH1 and MSH2 genes.
METHODS: Carriers of pathogenic variants of MLH1 (path_MLH1) and MSH2 (path_MSH2) genes filed in the Prospective Lynch Syndrome Database (PLSD) were categorized as truncating or missense/aberrant splicing according to the InSiGHT criteria for pathogenicity.
RESULTS: Among 5199 carriers, 1045 had missense or aberrant splicing variants, and 3930 had truncating variants. Prospective observation years for the two groups were 8205 and 34,141 years, respectively, after which there were no significant differences in incidences for cancer overall or for colorectal cancer or endometrial cancers separately.
CONCLUSIONS: Truncating and missense or aberrant splicing pathogenic variants were associated with similar average cumulative incidences of cancer in carriers of path MLH1 and path_MSH2.

BACKGROUND: Autosomal forms of Alport syndrome represent 20% of all patients (15% recessive and 5% dominant). They are caused by mutations in the COL4A3 and COL4A4 genes, which encode a-3 and a-4 collagen IV chains of the glomerular basement membrane, cochlea and eye. Thin basement membrane nephropathy may affect up to 1% of the population. The pattern of inheritance in the 40% of cases is the same as autosomal dominant Alport syndrome: heterozygous mutations in these genes. The aim of this study is to detect new pathogenic mutations in the COL4A4 gene in the patients previously diagnosed with autosomal Alport syndrome and thin basement membrane nephropathy in our hospital.
METHODS: We conducted a clinical and genetic study in eleven patients belonging to six unrelated families with aforementioned clinical symptoms and a negative study of COL4A3 gene. The molecular study was made by conformation of sensitive gel electrophoresis (CSGE) and direct sequencing of the fragments that show an altered electrophoretic migration pattern.
RESULTS: We found two pathogenic mutations, not yet described: IVS3 + 1G > C is a replacement of Guanine to Cytosine in position +1 of intron 3, in the splicing region, which leads to a pathogenic mutation. c.4267C > T; p.P1423S is a missense mutation, also considered pathogenic. We also found seven new polymorphisms.
CONCLUSIONS: We describe two new pathogenic mutations, responsible for autosomal dominant Alport syndrome. The other families of the study were undiagnosed owing to problems in the method employed and the possibility of mutations in other genes, giving rise to other diseases with similar symptoms.