Folate gene polymorphisms CBS 844ins68 and RFC1 A80G and risk of Down syndrome offspring in young Iranian women: A cross-sectional study.

Background: Cytogenetics and association studies showed that folate gene polymorphisms can increase the risk of chromosomal nondisjunction and aneuploidies. The folate-metabolizing gene polymorphisms in Down syndrome mothers (DSM) have been assessed in a variety of populations. Reduced folate carrier 1 (RFC1) and cystathionine beta-synthase (CBS) are key enzymes in folate metabolism. Objective: 2 common polymorphisms, CBS 844ins68 and RFC1 A80G, were analyzed to determine their probable risk for having Down syndrome (DS) babies in young mothers of Khuzestan province, Iran. Materials and Methods: This study was conducted on 100 mothers who had trisomy 21 DS children. 100 age- and ethnic-matched mothers with at least 2 healthy children and no history of abnormal pregnancies were considered as control. The samples were collected from all the mothers from June 2019 to April 2021. Genomic DNA was extracted from peripheral blood. The CBS-844ins68 and RFC1-A80G were genotyped using polymerase chain reaction-electrophoresis and restriction fragment length polymorphism, respectively. Results: The frequency of RFC1 AG and GG genotypes in DSM was significantly higher than the control mothers (odds ratio [OR] of 2.38 and 3.07, respectively). The heterozygote genotype of CBS 844ins68 was significantly more prevalent among DSM than the control (OR: 2.419). The OR was significantly increased to 6.667 when the homozygote of both variants was found together. Conclusion: Studying polymorphisms possibly increases the susceptibility of having a DS child. However, ethnicity, nutrition, and epistatic interactions are considerable factors to be evaluated in future studies.

miR-155 rs767649 T>A gene polymorphism is associated with downregulation of miR-155 expression, suppressor of cytokine signaling-1 overexpression, and low probability of metastatic tumor at the time of breast cancer diagnosis.

Background: MicroRNA-155 is a key player in inflammatory reactions, carcinogenesis, and tumor development. In this study, polymorphism of miRNA-155 rs767649 T>A and its gene and suppressor of cytokine signaling-1 (SOCS-1) expression were investigated in relation to cancer susceptibility and development in breast cancer (BC) patients. Materials and Methods: Polymorphism of miRNA-155 rs767649 T>A was evaluated between a population of 174 patients with BC and 129 controls using restriction fragment length polymorphism and the expression of miR-155 and SOCS-1 were examined in peripheral blood mononuclear cells (PBMCs) by real-time polymerase chain reaction. Results: TT genotype of miR-155 rs767649 T>A was associated with higher level of miR-155 in PBMCs of BC patients relative to AT and AA genotypes (21.76 ± 4.4, 4.046 ± 1.35, 2.56 ± 0.81, respectively; P < 0.001) and increased lymph node metastasis (r = 0.292, P = 0.001), not BC susceptibility (P = 0.402 and P = 0.535; respectively). TT genotype of miR-155 rs767649 T>A was associated with less gene expression of SOCS-1 in PBMCs of BC patients compared to AT and AA genotypes (1.173 ± 0.57, 0.92 ± 0.827, 5.512 ± 0.92, respectively; P = 0.003). Conclusion: This study demonstrated for the first time the association between the T allele of the rs767649 T>A polymorphism in the pre-MIR155 gene and higher expression of miR-155, lower expression of SOCS-1, and swift latent progression in newly diagnosed BC patients. Thus, miR-155 may play a critical role in BC pathogenesis.

Evaluation of BRCA1 Gene Promoter Methylation Status in Sporadic Breast Cancer Patients in Southwest of Iran.

OBJECTIVE: Similar to other types of cancer, the development of breast cancer is a multi-stage process, consisting of various mutations and epigenetic changes in many genes. Mutations in the BRCA1 gene, which is a tumor suppressor gene, are considered as the most important types of mutations. The pivotal role of epigenetics is currently considered as the primary key to carcinogenesis. Several studies have previously reported the BRCA1 epigenetic silencing through promoter methylation in the pathophysiology of breast cancer cells. This study aimed to investigate whether the BRCA1 gene promoter methylation in peripheral blood cells is correlated with the risk of breast cancer. METHODS: In the current study, DNA samples were extracted from blood cells belonged to 74 patients with breast cancer as well as 30 healthy individuals, and the BRCA1 gene promoter methylation status in these two groups was examined using Methylation Specific PCR (MSP). RESULT: out of 74 patients, 2 cases demonstrated methylation in their BRCA1 gene promoter; however, none of the healthy controls demonstrated methylation status. Among these 74 patients, 13 cases were at the early stages (stage I), and two patients who had BRCA1 gene methylation (15.4%), were in this group (p=0.02). While 34 and 27 patients were at stages II and III, respectively, showing a negative state of BRCA1 gene methylation. CONCLUSION: Although 2 out of 74 patients resulted positive for methylation status, the healthy controls demonstrated no methylation. Consequently, there was inadequate evidence to confirm the association between BRCA1 gene promoter methylation in blood and the risk of developing breast cancer.

Altered Expression Levels of MicroRNA-155 and SOCS-1 in Peripheral Blood Mononuclear Cells of Newly Diagnosed Breast Cancer Patients.

MicroRNA-155 (miR-155) has a critical role in pro-inflammatory activation and tumor progression. In addition, miR-155 has various oncogenic effects in the tumor microenvironment by targeting the suppressor gene of cytokine signaling-1(SOCS-1) and interleukin-6 (IL-6). This study investigated the association of inflammatory changes with the variations of miR-155 expression in newly diagnosed breast cancer (NDBC) patients. Seventy NDBC patients were categorized as lobular and ductal subgroups and forty healthy individuals participated in this study. The expression rate of miR-155 and its downstream target gene, SOCS-1, as well as the plasma levels of IL-6, were evaluated in peripheral blood mononuclear cells of NDBC patients; using real-time PCR and enzyme-linked immunosorbent assay, respectively. Our results indicated an over-expression of miR-155 in the PBMCs of NDBC patients which was significantly associated with the tumor grade and the type of ductal carcinoma. In contrast, a significant downregulation of SOCS-1 was observed in NDBC patients compared to control group, however, there was no significant difference between two subtypes of BC. Furthermore, a higher concentration of plasma IL-6 was detected in NDBC patients compared to the healthy control group which had an inverse correlation with the SOCS-1 levels. According to the potential effects of miR-155 on regulating the expression of SOCS-1 and IL-6, we suggest this small transcript as a promising diagnostic marker for various types of BC patients.

DNA vaccine containing Flagellin A gene induces significant immune responses against Helicobacter pylori infection: An in vivo study.

OBJECTIVES: Helicobacter pylori is one of the most prevalent human infectious agents that is directly involved in various upper digestive tract diseases. Although antibiotics-based therapy and proton pump inhibitors eradicate the bacteria mostly, their effectiveness has been declined recently due to emergence of antibiotic-resistant strains. Development of a DNA vaccine is a promising approach against bacterial pathogens. Genes encoding motility factors are promising immunogens to develop a DNA vaccine against H. pylori infection due to critical role of these genes in bacterial attachment and colonization within the gastric lumen. The present study aimed to synthesize a DNA vaccine construct based on the Flagellin A gene (flaA), the predominant flagellin subunit in H. pylori flagella. MATERIALS AND METHODS: The coding sequence of flaA was amplified through PCR and sub-cloned in the pBudCE4.1 vector. The recombinant vector was introduced into the human dermal fibroblast cells, and its potency to express the flaA protein was analyzed using SDS-PAGE. The recombinant construct was intramuscularly (IM) injected into the mice, and the profiles of cytokines and immunoglobulins were measured using ELISA. RESULTS: It has been found that flaA was successfully expressed in cells. Recombinant-vector also increased the serum levels of evaluated cytokines and immunoglobulins in mice. CONCLUSION: These findings showed that the pBudCE4.1-flaA construct was able to activate the immune responses. This study is the first step towards synthesis of recombinant-construct based on the flaA gene. Immunization with such construct may inhibit the H. pylori-associated infection; however, further experiments are urgent.

Transcription Factors of CAT1, EFG1, and BCR1 Are Effective in Persister Cells of Candida albicans-Associated HIV-Positive and Chemotherapy Patients.

BACKGROUND: Biofilm is an accumulation of cells, which are formed on mucosal surfaces of the host as well as on medical devices. The inherent resistance of Candida strains producing biofilms to antimicrobial agents is an important and key feature for biofilm growth, which can lead to treatment failure. This resistance is due to the regulatory increase of the output pumps, the presence of extracellular matrix, and the existence of persister cells. Persister cells are phenotypic variants that have MICs similar to antibiotic-sensitive populations and are able to tolerate high doses of antibiotics. The current study investigated the possible role of EFG1, BCR1, and CAT1 in the establishment or maintenance of persister cells in Candida albicans strains that produce biofilms. METHODS: After identifying Candida isolates by molecular methods, C. albicans isolates were confirmed by sequencing. Isolation of persister cells and determination of their MIC were performed by microdilution method. Then, RNA extraction and cDNA synthesis were performed from 60 C. albicans isolates under promoting and inducing conditions. Afterward, the mean expression of BCR1, EFG1, and CAT1 genes in both persister and non-persister groups was calculated using real-time qPCR. Phylogeny tree of persister and non-persister group isolates was drawn using ITS fragment. RESULTS: A total of 77 persister isolates were taken from the oral cavity of HIV patients as well as from patients undergoing chemotherapy. Biofilm intensity in persister isolates separated from HIV-infected patients was different from the non-persister group. The mean fold change of BCR1 (10.73), CAT1 (15.34), and EFG1 (2.41) genes in persister isolates was significantly higher than these genes in isolates without persister. CONCLUSION: It can be concluded that the most important factor in the production of persister cells is biofilm binding and production, not biofilm development or mature biofilm production, which was found in the expression of BCR1 gene without change in the expression of EFG1 gene in the persister group. Also, catalase plays an essential role in the production of persister in C. albicans biofilm producers with ROS detoxification.

The pattern of gene copy number alteration (CNAs) in hepatocellular carcinoma: an in silico analysis.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common type of liver cancer that occurs predominantly in patients with previous liver conditions. In the absence of an ideal screening modality, HCC is usually diagnosed at an advanced stage. Recent studies show that loss or gain of genomic materials can activate the oncogenes or inactivate the tumor suppressor genes to predispose cells toward carcinogenesis. Here, we evaluated both the copy number alteration (CNA) and RNA sequencing data of 361 HCC samples in order to locate the frequently altered chromosomal regions and identify the affected genes. RESULTS: Our data show that the chr1q and chr8p are two hotspot regions for genomic amplifications and deletions respectively. Among the amplified genes, YY1AP1 (chr1q22) possessed the largest correlation between CNA and gene expression. Moreover, it showed a positive correlation between CNA and tumor grade. Regarding deleted genes, CHMP7 (chr8p21.3) possessed the largest correlation between CNA and gene expression. Protein products of both genes interact with other cellular proteins to carry out various functional roles. These include ASH1L, ZNF496, YY1, ZMYM4, CHMP4A, CHMP5, CHMP2A and CHMP3, some of which are well-known cancer-related genes. CONCLUSIONS: Our in-silico analysis demonstrates the importance of copy number alterations in the pathology of HCC. These findings open a door for future studies that evaluate our results by performing additional experiments.

Identification of the PRM1 gene mutations in oligoasthenoteratozoospermic men.

Mutations or altered expression of PRM1 gene have been associated with male infertility. This study aimed to analyse pathogenic variations of PRM1 gene in Iranian Arab infertile men with oligoasthenoteratozoospermia that was carried out for the first time in this population. Genomic DNA was used to perform PCR sequencing in PRM1 untranslated regions, exons and intron. Also, bioinformatics analysis was recruited to discover the possible effect of detected variations. Two pathogenic variations were seen in two men with oligoasthenoteratozoospermia, which were not found in the control group. The cDNA.384G>C variation is novel and was located in the 3' untranslated region, and cDNA.42G>A variation is reported for the first time related to male infertility and was found in 5' untranslated regions. Bioinformatics analysis showed that the minimum free energy was increased from -19.9kcal/mol to -13.1kcal/mol due to the cDNA.384G>C variation at hsa-miR-4326's seed site. More analysis revealed cDNA.42G>A located in transcription factors binding site, E1 and MYOD, which was detected as a promoter-associated region, and generally have regulatory features for acetylation and methylation. In conclusion, two pathogenic variations were recognised in regulatory areas of PRM1 gene, which might interfere with some critical factors related to PRM1 gene expression, hence cause male infertility.

Increased Expression Level of Long Noncoding RNA H19 in Plasma of Patients with Myocardial Infarction.

Long noncoding RNAs (lncRNAs) are lengthy noncoding transcripts which are actively involved in crucial cellular pathways. Tissue-specific expression of lncRNAs besides its secretion into the body fluids, has made lncRNAs in attention as biomarkers of the diseases. According to the role of lncRNAs, especially H19 in cardiac regeneration, it is not surprising if their altered expression levels lead to cardiac diseases. In the present study, the relative expression of H19 was compared in the plasma of atherosclerotic myocardial infarction and control individuals by real time-PCR, and data were normalized using GAPDH. The association of plasma level of lipid and homocystine with H19 expression was also considered. The potential of H19 to discriminate the case from control was studied using the ROC analysis. We found that the plasma level of H19 transcript significantly increased in the plasma of patients in comparison with the control group. Additionally, the relative expression level of H19 was directly associated with the plasma homocystine level. The relative expression of H19 at threshold of 0.3 showed 70% sensitivity and 94% specificity to discriminate cases from controls. This study revealed that the expression level of H19 may be considered as a biomarker of myocardial infarction, although further studies are needed to generalize this finding.

Oral colonization by Candida species and associated factors in HIV-infected patients in Ahvaz, southwest Iran.

OBJECTIVES: Oropharyngeal candidiasis is one of the most common opportunistic fungal infections among human immunodeficiency virus (HIV)-infected individuals. The most common cause is Candida albicans, followed by non-albicans Candida. This study aimed to identify colonized Candida species in HIV-infected patients from Ahvaz, Iran. Additionally, the relationships between immunity-related factors, lifestyle, and colonization of Candida spp. were studied. METHODS: Oral swabs were taken from 201 HIV-positive patients referred for consultations at the Behavioral Modification Center. Oral Candida colonization was detected using culture-based and molecular assays. Data were assessed by descriptive statistics and analyzed to investigate the correlation between Candida colonization and various factors, including the CD4+ cell count and viral load. RESULTS: It was found that 43.8% of patients were positive for Candida. The most common species was C. albicans (48.0%), followed by non-albicans Candida isolates, including C. dubliniensis, C. glabrata, C. tropicalis, C. parapsilosis, C. guilliermondii, C. kefyr, and C. krusei. Colonization of Candida spp. in patients was associated with a CD4 count ≤200 cells/mm3 (odds ratio [OR], 4.62; p<0.05), history of shared injections (OR, 6.96; p<0.001), and sex (OR, 3.59; p<0.05). CONCLUSIONS: The results of this study showed that C. albicans was the dominant pathogen. The risk factors for colonization of Candida spp. were a CD4 count ≤ 200/mm3 , a history of shared injections, and sex. Other factors with potential relationships include viral load, age, and opportunistic infections, but further investigations are needed.

SNHG1 Long Noncoding RNA is Potentially Up-Regulated in Colorectal Adenocarcinoma.

Colorectal cancer (CRC) is one of the most common types of cancer worldwide. However, the molecular mechanisms involved in CRC initiation and progression is remained to be unknown. It seems that lncRNAs, as the main and lengthy functional transcripts of the genome, have important roles in different cancers such as CRC. CRC-related lncRNAs are reported to be involved in diverse molecular processes such as metastasis, invasion, cell proliferation, and apoptosis. This study was aimed to analyse the expression level of lncRNA SNHG1 in colorectal adenocarcinoma and normal tissues. We performed an in silico analysis on a large cohort and confirmed the results by experimental analysis of clinical samples through real-time PCR. Our findings demonstrated that that SNHG1 is potentially overexpressed in tumor tissues compared with adjacent normal tissues. The expression level of SNHG1 was shown to be potentially associated with clinicopathological features of tumors. The current study suggests the potential role of SNHG1 in colon cancer progression.

Whole exome sequencing identified a novel nonsense INPP4A mutation in a family with intellectual disability.

Intellectual disability (ID) is characterized by significant deficits in adaptive behaviors and cognitive functioning. The involvement of both genetic and environmental factors in pathogenesis of the ID, makes the diagnosis of the disease more complicated. Nowadays, the entrance of next generation sequencing (NGS) approaches has facilitated the discovery of causative genes in this genetically heterogeneous disease. Here, we report a novel nonsense mutation (c.115 C > T, p.Gln39X) of INPP4A gene in a family with inherited ID using whole exome sequencing (WES). The mutation was completely co-segregated with disease phenotype in all affected members, and unaffected members of family were either homozygous or heterozygous. In silico analysis predicted the c.115 C > T; p.Gln39X as probably pathogenic variant. It seems that mutated transcript would degrade through nonsense-mediated decay (NMD) or potentially form strongly truncated protein lacking functionally important domain like C2A_copine. The INPP4A is an important neuroprotective protein which is preferentially detected in brain. The variant c.115C > T; p.Gln39X is the third reported mutation of INPP4A gene in neurological diseases. Such variants further expand the mutation spectrum in INPP4A and substantiate its role in the pathogenesis of ID. However, more experimental data are needed for considering these mutations in genetic counseling.

Overexpression of microRNA-21 in the Serum of Breast Cancer Patients.

BACKGROUND: Breast cancer is the most common cancer diagnosed in women worldwide. So it seems that there's a good chance of recovery if it's detected in its early stages even before the appearances of symptoms. Recent studies have shown that miRNAs play an important role during cancer progression. These transcripts can be tracked in liquid samples to reveal if cancer exists, for earlier treatment. MicroRNA-21 (miR-21) has been shown to be a key regulator of carcinogenesis, and breast tumor is no exception. OBJECTIVE: The present study was aimed to track the miR-21 expression level in serum of the breast cancer patients in comparison with that of normal counterparts. METHODS: Comparative real-time polymerase chain reaction was applied to determine the levels of expression of miR-21 in the serum samples of 57 participants from which, 42 were the patients with breast cancer including pre-surgery patients (n = 30) and post-surgery patients (n = 12), and the others were the healthy controls (n = 15). RESULTS: MiR-21 was significantly over expressed in the serum of breast cancer patients as compared with healthy controls (P = 0.002). A significant decrease was also observed following tumor resection (P < 0.0001). Moreover, it was found that miR-21 overexpression level was significantly associated with tumor grade (P = 0.004). CONCLUSION: These findings suggest that miR-21 has the potential to be used as a novel breast cancer biomarker for early detection and prognosis, although further experiments are needed.

Exome sequencing revealed a p.G299R mutation in the COMP gene in an Iranian family suffering from pseudoachondroplasia.

BACKGROUND: Short-stature (SS) is multifactorial pathologic condition that originates from either genetic or environmental factors. The diagnosis is based on family history, clinical findings, radiological examination and genetic analysis. A variety of genes have been reported for SS, among which FGFR-3 was the main gene in achondroplasia and hypochondroplasia. In other forms of SS, the gene involved varies from one patient to another. Whole exome sequencing (WES) and comparative genomic hybridization (CGH) have recently introduced a growing body of genes annually. The present study performed a WES analysis on an Iranian family suffering from an inherited form of SS aiming to diagnose the causative gene. The father and all of his four sons were diagnosed as SS. METHODS: The blood samples were collected from the proband and his available family members. Genomic DNA was extracted using salting-out method. The DNA of the proband was analyzed using WES and confirmed through polymerase chain reaction (PCR)-sequencing. The WES-extracted variant was evaluated in silico using software aiming to determine whether this nucleotide change is pathogenic. The presence of the variant was traced in other affected family members using PCR-sequencing. RESULTS: Following segregation analysis, variant c.896 G>A of the COMP gene was found in all of the affected individuals in a heterozygous form. This variant resulted in substitution of glycine 299 with arginine and was previously predicted as pathogenic in the Human Gene Mutation Database dataset, although it represents the first report in Iran. CONCLUSIONS: The findings of the present study suggest consideration of the c.896 G>A variant of the COMP gene with respect to the genetic counseling of inherited skeletal dysplasia in Iran.

Study of the immunogenicity of outer membrane protein A (ompA) gene from Acinetobacter baumannii as DNA vaccine candidate in vivo.

OBJECTIVES: Acinetobacter baumannii is one the most dangerous opportunistic pathogens in hospitalized infections. This bacterium is resistant to 90% of commercial antibiotics. Therefore, developing new strategies to cure A. baumannii-infections is urgent. The DNA vaccines new approach in which the immunogen can be directly expressed inside the target cells through cloning of immunogen into an expression vector. The outer membrane protein A(OmpA) is one the critical factors in pathogenicity of A. baumannii which has been repeatedly described as a powerful immunogen to trigger the immune responses. As the pure form of the OmpA is insoluble, vaccine delivery is very hard. MATERIALS AND METHODS: We previously cloned the ompA gene from A. baumannii into the eukaryotic expression vector pBudCE4.1 and observed that the OmpA protein has been considerably expressed in eukaryotic cell model. In current study, the immunogenic potential of pBudCE4.1-ompA has been evaluated in mice model of experimental. The serum levels of IgM, IgG, IL-2, IL-4, IL-12 and INF-γ were measured by enzyme-linked immunosorbent assay (ELISA) after immunization with ompA-vaccine. The protective efficiency of the designed-DNA vaccine was evaluated following intranasal administration of mice with toxic dose of A. baumannii. RESULTS: Obtained data showed the elevated levels of IgM, IgG, IL-2, IL-4, IL-12 and INF-γ in serum following the vaccine administration and mice who immunized with recombinant vector were survived more than control group. CONCLUSION: These findings indicate ompA-DNA vaccine is potent to trigger humoral and cellular immunity responses although further experiments are needed.

Whole exome sequencing revealed a novel dystrophin-related protein-2 (DRP2) deletion in an Iranian family with symptoms of polyneuropathy.

OBJECTIVES: Charcot-Marie Tooth disease (CMT) is one of the main inherited causes of motor and sensory neuropathies with variable expressivity and age-of onset. Although more than 70 genes have been identified for CMT, more studies are needed to discover other genes involved in CMT. Introduction of whole exome sequencing (WES) to capture all the exons may help to find these genes. MATERIALS AND METHODS: Here, we tried to find the genetic cause of the neuropathy in two Iranian brothers using WES. Blood sample was collected from probands and their family members to extract the genomic DNA. The extracted DNA from one of the affected case was subjected for WES. The variant calls were filtered to reveal the pathogenic variant. Presence of the candidate mutation was confirmed using Sanger sequencing. The pathogenic potential of the variant was examined using in silico software. Using ClustalW multiple alignment, the presence of variant in conserved domain of protein was investigated. The parent and another affected boy were also checked for presence of the variant using PCR-sequencing. RESULTS: The obtained data presented a novel TTC del mutation in CDS 738 of dystrophin related protein 2 (DRP2) gene, which was validated by sequencing. The variant was located in a conserved domain of DRP2 protein and predicted as pathogenic. Two affected boys were hemizygous for the mutation and received the mutation from mother. CONCLUSION: Here, we provided the evidence for the contribution of DRP2 in CMT. Also, the symptoms shed light on molecular aspect of this genetically heterogeneous disease.

Defective mitosis-linked DNA damage response and chromosomal instability in liver cancer.

Hepatocellular carcinoma (HCC), the most common form of liver cancer, represents a health problem in hepatic viruses-eradicating era because obesity, type 2 diabetes, and nonalcoholic steatohepatitis (NASH) are considered emerging pathogenic factors. Metabolic disorders underpin mitotic errors that lead to numerical and structural chromosome aberrations in a significant proportion of cell divisions. Here, we review that genomically unstable HCCs show evidence for a paradoxically DNA damage response (DDR) which leads to ongoing chromosome segregation errors. The understanding of DDR induced by defective mitoses is crucial to our ability to develop or improve liver cancer therapeutic strategies.

Exome sequencing found a novel homozygous deletion in ADCK3 gene involved in autosomal recessive spinocerebellar ataxia.

Autosomal recessive cerebellar ataxia is heterogeneous inherited neurodegenerative disorders with more than 70 involved genes. The development of next generation sequencing opens a new window in rapid diagnosis of such heterogeneous condition in medical genetics laboratories. Here, we present ADCK3; del.CD (229-230) mutation in an Iranian consanguineous family with three cerebellar ataxic boys using whole exome sequencing. The mutation was predicted pathogenic and all the affected individuals were homozygous for the variant. Although, the ADCK3 was previously reported as one of the master genes of ARSC, our mutation was novel as has been not previously reported in dbSNP or literature.

A novel infram deletion in MSH6 gene in glioma: Conversation on MSH6 mutations in brain tumors.

OBJECTIVE AND BACKGROUND: Histological and molecular information and biopsy help in the diagnosis of the type and grade of tumors and increase the value of estimation of the biological behavior of tumors. In this study, we focused on a consanguineous Iranian Family with high prevalence of brain tumors in their pedigree and reviewed the literature on MSH6 mutations in brain tumors and the treatment responses focused on Gliomas. METHOD: We chose a family with a high prevalence of brain tumor in their pedigree. We studied the proband's neuroimaging and brain proton magnetic resonance spectroscopy (MRS), magnetic resonance imaging (MRI), biopsy result, and whole-genome sequencing. RESULT: The neuroimaging and brain proton MRS reported a lesion in the right frontoparietal. The MRI revealed a large enhancible heterogenous mass in the right temporo-fronto-parieto-occipital lobes with involvement of corpus callosum which was suggestive of glioma. The patient revealed a homozygous pattern for a novel 9 base-pare deletion at the 912-914 codon on exon 4 of the MSH6 gene. DISCUSSION: We discuss several studies on MSH6 mutations in brain tumors and we discuss treatment responses in MSH6 mutations and the studies conducted to sensitize chemotherapy and radiotherapy resistance brain tumors to face this subject efficiently. CONCLUSION: Patients should be evaluated for MMR mutation before chemo and radiotherapy, and it is valuable to follow-up these mutations during the treatment too. In temozolomide (TMZ)-resitance cases, it is suggested to use complementary strategies such as using HDACis and a combination of a STAT3 Inhibitor and an mTOR inhibitor, BER inhibition mechanism, and PARP-1 inhibitor.

Genotype-phenotype correlation and the size of microdeletion or microduplication of 7q11.23 region in patients with Williams-Beuren syndrome.

Williams-Beuren syndrome (WBS) is a chromosomal microdeletion syndrome with variable phenotypic features such as supravalvular aortic stenosis (SVAS), facial appearance characteristics, growth retardation, and infantile hypercalcemia. This study aimed to detect the 7q11.23 microdeletion in 10 patients with early clinical diagnosis of WBS using fluorescent in situ hybridization or array comparative genomic hybridization. As an alternative method, multiplex ligation-dependent probe amplification (MLPA) was used to confirm this microdeletion. Clinical features were also compared with detected genotypes. To reveal the parental origin of deletion, four polymorphic markers (D7S1870, D7S489, D7S613, and D7S2476) were used. The deletion had maternal origin in 80% and paternal origin in 20% of the cases. From 10 patients with early clinical diagnosis of the WBS, 3 patients presented with atypical phenotypes such as infantile hypocalcemia, normal IQ, and normal facial characterization, but the sizes of their deletions seemed to be almost similar to other cases. Regarding such observation, we suggest that the phenotypic variations of WBS are influenced not only by the deletion size and involving genes but also by the breakpoint regions and probably epigenetic effects. However, further research is required to explore the effect of such parameters on phenotypic features.