Investigation of germline VHL variants in Iranian patients with retinal capillary hemangioblastoma and genotype-phenotype analysis.

BACKGROUND: Retinal capillary hemangioblastoma (RCH), while sporadic in some cases, is the most common and earliest manifestation of von Hippel-Lindau disease (VHL). This is the first report on different types of VHL variants and genotype-phenotype correlations in Iranian families with RCH. MATERIALS AND METHODS: In this prospective observational case series study, 17 families with RCH were included. PCR was performed to amplify 3 exons of VHL gene. Afterward, Sanger sequencing was performed on all PCR products. For the detection of VHL copy number variations, MLPA was used. RESULTS: Our study identified 10 different types of VHL variants. Missense mutations were the most common variants found and affected the structure of α domain of the VHL protein (pVHL). The majority of mutations (72.7%) in the patients with RCH and central nervous system hemangioblastoma (CNS-HB) were located on α domain. CONCLUSION: α domain of VHL may play a potential role in the pathogenesis of RCH. Our findings suggest that genotype-phenotype characteristics in those variants in α- domain may predispose patients to RCH with CNS-HB.

A meta-analysis of different von Hippel Lindau mutations: are they related to retinal capillary hemangioblastoma?

Retinal capillary hemangioblastomas (RCH) is a benign tumor that represents the initial manifestation in roughly half of Von Hippel Lindau (VHL) patients. They may also occur sporadically without systemic involvement. A first meta-analysis study was investigated to estimate the prevalence of Retinal capillary hemangioblastoma (RCH) in Von Hippel Lindau (VHL) syndrome, and its relation to type and location of mutations in VHL gene. The electronic databases of PubMed, Scopus, Embase, and Google Scholar were utilized to find eligible papers published up to May 2020. Lastly, after the different prevalence of RCH in Europe compared to other continents was noted, we decided to consider European and non-European patients separately. The Random effect model was used to evaluate the relation between developing RCH and types of mutations. The overall prevalence of RCH among VHL patients is about 47%. The prevalence of RCH was significantly higher in Europe in comparison with non-Europeans (p value < 0.001). Overall, the differences between the prevalence of RCH among different mutation types were not statistically significant. However, in Europe, the prevalence of RCH was significantly higher in patients with truncation mutation (p value = 0.007). In Europe, the RCH in VHL patients who had a mutation in exon 2 was significantly lower in comparison with exon 1 (p value = 0.001); but in non-Europeans, the prevalence of RCH in VHL patients that involved exon 2 was significantly higher in comparison with VHL patients with a mutation in exon1 (p value = 0.012). The highest risk of developing RCH was reported among Europeans. Overall, this study showed that the prevalence of RCH in VHL syndrome is not related to type or location of mutations and difference of RCH prevalence is probably depends on other genetic or environmental factor that should be considered in subsequent studies.

Use of expanded carrier screening for retrospective diagnosis of two deceased siblings with Van Maldergem syndrome 2: case report.

Van Maldergem syndrome (VMLDS) is a recessive disease which affects multiple organs including the face, ear, and limb extremities. It can be caused by pathogenic variants in either the gene DCHS1 or FAT4. Diagnosis of VMLDS is complicated, especially regarding its similarity of symptoms to Hennekam syndrome, another disorder caused by FAT4 variants. Reported patients are two infantile siblings with multiple congenital anomalies, who deceased without clinical diagnosis. Whole exome sequencing was exploited for expanded carrier screening (ECS) of their parents, which revealed a novel splicing variant in the gene FAT4, NM_024582.6: c.7018+1G>A. In silico analysis of the variant indicates loss of canonical donor splice site of intron 6. This variant is classified as pathogenic based on ACMG criteria. Reverse phenotyping of patients resulted in likely diagnosis of VMLDS2. This study reaffirms the possibility of using ECS, leading to the genetic diagnosis of a rare disease with complicated clinical features.

Young Breast Cancer: Novel Gene Methylation in WBC.

INTRODUCTION: Breast cancer is a highly diverse disease, and epigenomic alterations, as principle changes in the pathogenesis of breast cancer, have recently been noticed in epimarker research on peripheral blood. METHODS: In this study, DNA samples isolated from the white blood cells of 30 breast cancer patients were compared to 30 healthy controls using methylated DNA immunoprecipitation microarray (MeDIP-chip) to determine differentially methylated region as a potential epimarker in cancer and control cases. RESULTS: A total of 1799 differentially methylated regions were identified, including ZNF154, BCL9, and HOXD9, in which significant methylation differences were confirmed in breast cancer patients through a quantitative real-time polymerase chain reaction. Differential methylation of the mentioned genes has been reported in different cancer tissues and cell-free DNA, including breast cancer. Methylation of those genes listed in the white blood cells of our young patients not only relates to their importance in the pathogenesis of breast cancer but may also highlight their potential as primary epimarkers that can warrant further evaluation in large cohort studies. It is important to note that methylation alteration in WBC, as well as genetic mutation, can be identified years before cancer development, which emphasizes this issue as a potential screening marker.

Identification of MiR-125a as a Novel Plasma Diagnostic Biomarker for Chronic Lymphoblastic Leukemia.

Background: Chronic lymphocytic leukemia (CLL) is a type of malignancy in which the bone marrow makes too many lymphocytes. MicroRNAs (miRNAs) are endogenous short (~22-nucleotides) non-protein-coding regulatory RNA molecules with key roles in cellular and molecular processes linked to different cancers including CLL. Re-cently, some investigations have demonstrated that miR-125a downregulation is correlated with the expression of P53, NRG1 and ERBB2. Methods: In this study, samples including 38 patients with CLL and 25 healthy individuals were collected. We used quantitative real-time PCR (qRT-PCR) to assess the expression of miR-125a in plasma of the CLL patients in comparison with healthy controls. Moreover, we used the Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathway analysis on miR-125a targets in the DAVID database in order to investigate the potential role of miR-125a in cancer pathways. MiR-125a exerted a variety of roles in the cancer pathway via downregulating target genes including ERBB2. Results: The expression of miR-125a dramatically decreased (~2-fold) in the patients with CLL compared with the healthy controls (p = 0.03). Furthermore, overexpression of miR-125a was associated with different CLL staging and B symptoms (all at p < 0.05). The KEGG pathway enrichment analysis demonstrated the eight statistically related KEGG signaling pathways with miR-125a targetome. Conclusions: The results suggested that the miR-125a expression level could be a novel potential biomarker for CLL prognosis.

Over expression of circulating miR-155 predicts prognosis in diffuse large B-cell lymphoma.

INTRODUCTION: The expression patterns of microRNAs in plasma are involved in potential biomarkers for several diseases. The goal of this study was to explore the expression level of miR-155 in diffuse large B-cell lymphoma (DLBCL) and its clinical significance. MATERIALS AND METHODS: We used qRT-PCR to assess the peripheral blood plasma of 40 DLBCL patients for the expression of miRNA-155. The median of miR-155 expression divided the DLBCL patients into miR-155 low-expression (miR-155low) and miR-155 high-expression (miR-155high) groups. RESULTS AND DISCUSSION: We found that plasma miR-155 expression was significantly up-regulated in patients with DLBCL (median expression value: 4.29, range: 1.52-27.86) compared to healthy individuals (median expression value: 2.14, range: 0.29-10.56, P < 0.002). Moreover, DLBCL cases with an elevated level of miR-155 had shorter overall survival (median 9 vs. 13 months, P = 0.043) than those with a lower miR-155 expression.

Genetic Screening of Iranian Patients with 46,XY Disorders of Sex Development.

BACKGROUND: Disorders of sex development (DSDs) belong to uncommon pathologies and result from abnormalities during gonadal determination and differentiation. Various gene mutations involved in gonadal determination and differentiation have been associated with gonadal dysgenesis. Despite advances in exploration of genes and mechanisms involved in sex disorders, most children with severe 46,XY DSDs have no definitive etiological diagnoses; therefore, the possibility that other genes or loci might play important roles in these disorders needs to be explored. METHODS: Patients (37) clinically suspicious for 46,XY gonadal dysgenesis (46,XY GD) of unknown etiology were studied. SRY, encoding the sex-determining region Y protein, NR5A1, encoding a transcription factor called steroidogenic factor 1, and DHH, encoding the desert hedgehog protein, were directly sequenced. Multiplex ligation-dependent probe amplification (MLPA) was used to detect deletions in NR0B1, encoding the DAX1 protein, and WNT4, encoding the WNT4 protein, and real-time PCR (qPCR) confirmed the MLPA data. Other potential loci have been investigated in the complete genome using Array-Comparative Genomic Hybridization, (Array CGH). RESULTS: The SRY deletion was found in five patients. One each of previously described NR5A1, DHH, and AR (androgen receptor) allelic variants were identified. A pathogenic c.2522G>A AR mutation was found in two affected brothers. A heterozygous partial deletion was found in NR5A1 and heterozygous partial duplications were found in WNT4. These deletions and duplications (del/dup) were confirmed by qPCR. The Array CGH result demonstrated one partial deletion in SOX2-OT, which encodes a member of the SOX family of transcription factors, and the exact region of the rearrangements. CONCLUSION: According to our study, del/dup mutations could be checked prior to point mutations, SOX2-OT has a potential role in gonadal dysgenesis, and Array CGH has a prominent role in gonadal dysgenesis diagnosis.

Methylomics of breast cancer: Seeking epimarkers in peripheral blood of young subjects.

Critical roles of epigenomic alterations in the pathogenesis of breast cancer have recently seized great attentions toward finding epimarkers in either non-invasive or semi-non-invasive samples as well as peripheral blood. In this way, methylated DNA immunoprecipitation microarray (MeDIP-chip) was performed on DNA samples isolated from white blood cells of 30 breast cancer patients compared to 30 healthy controls. A total of 1799 differentially methylated regions were identified including SLC6A3, Rab40C, ZNF584, and FOXD3 whose significant methylation differences were confirmed in breast cancer patients through quantitative real-time polymerase chain reaction. Hypermethylation of APC, HDAC1, and GSK1 genes has been previously reported in more than one study on tissue samples of breast cancer. Methylation of those aforementioned genes in white blood cells of our young patients not only relies on their importance in breast cancer pathogenesis but also may highlight their potential as early epimarkers that makes further assessments necessary in large cohort studies.

DNA methylation as a promising landscape: A simple blood test for breast cancer prediction.

Breast cancer is the most common malignancy among women worldwide. Risk assessment is one of the main services delivered by cancer clinics. Biomarker analysis on different tissues including the peripheral blood can provide crucial information. One of the potential epigenetic biomarkers (epimarkers) is introduced as the peripheral blood DNA methylation pattern. This study was conducted to evaluate the potential value of peripheral blood epimarkers as an accessible tool to predict the risk of breast cancer development. WBC's DNA was the focus of several case-control studies at both genome wide and candidate gene levels to reveal epigenetic changes accounting for predisposition to breast cancer, leading to suggest that ATM, TITF1, SFRP1, NUP155, NEUROD1, ZNF217, DBC2, DOK7 and ESR1 genes and the LINE1, Alu and Sat2 DNA elements could be considered as the potential epimarkers. To address that by which mechanisms WBC's DNA methylation patterns could be linked to the propensity to breast cancer, several contemplations have been offered. Constitutional epimutation during embryonic life, and methylation changes secondary to either environmental exposures or tumor-mediated immune response, are the two main mechanisms. One can deduce that epimarkers based on their potential properties or regulatory impacts on cancer-related genes may be employed for risk prediction, prognosis, and survival inferences that are highly required for breast cancer management toward personalized medicine.