Identification of a novel truncating variant in AHI1 gene and a brief review on mutations spectrum.

Joubert syndrome (JS) is a rare inherited neurodevelopmental condition characterized by hypotonia, ataxia, developmental delay, abnormal eye movements, neonatal respiratory disturbance and unique midbrain-hindbrain malformation, known as the molar tooth sign. JS is a genetically heterogeneous disorder with nearly 35 ciliary genes are implicated in its pathogenesis. AHI1 gene is one of the most frequently mutated gene in JS patients which is accounted for 8-11% of cases, particularly in Arab population. AHI1 encodes a cilium-localized protein with a significant role in mediating vesicle trafficking, ciliogenesis and cell polarity. Here, we report a novel pathogenic variant in AHI1 gene and review previously published mutations in AHI1 gene briefly. Whole exome sequencing was employed to determine the causative mutation in an Iranian Arab family with JS from southwestern Iran. Segregation analysis of the candidate variant in the family members was performed using PCR-Sanger sequencing. This approach found a novel homozygous nonsense variant c.832C > T (p.Gln278Ter) in AHI1. Segregation analysis was consistent with individual's phenotype and an autosomal recessive pattern in the family. The variant residing in a relatively highly conserved region and fulfilled the criteria required to be classified as a pathogenic variant based on American College of Medical Genetics and Genomics guidelines. This study confirms the diagnosis of JS in this family and highlights the efficiency of next-generation sequencing-based technique to identify the genetic causes of hereditary disorders with locus heterogeneity.

A novel missense variant in EIF2B5 identified in a consanguineous Iranian family with vanishing white matter disease and a brief review of the literature.

Vanishing of white matter (VWM) is a hereditary heterogeneous brain disorder that most often affects children. However, the onset of the disease varies from childhood to adulthood. VWM is caused by mutations in one of the five genes encoding subunits of the eukaryotic initiation factor eIF2B. In the current study, we aimed to determine the genetic cause of VWM in a large consanguineous Iranian family with three affected members. Next-generation sequencing was conducted on the proband to determine the underlying cause of VWM. The identified variant was validated by PCR-Sanger sequencing in the patient and was also segregated in his parents and two other affected members of the pedigree. The potential functional effects of this mutation within EIF2B5 were predicted by in silico analysis. We have also reviewed all EIF2B5 disease-causing variants and available clinical features of each patient reported in HGMD Professional 2022.2. A novel homozygous variant c.746T>G [p.Ile249Ser] was detected in EIF2B5 which was co-segregated with the disease in all affected family members in an autosomal recessive manner. All employed in silico prediction tools and 3D structure analysis for the novel mutation also supported the pathogenicity of this variant. Our study not only expanded the spectrum of the pathogenic variants in EIF2B5 but also presented a literature review on EIF2B5-related conditions that provide a comprehensive picture of the genetic nature of this gene and phenotypic variability in patients.

Whole-Exome Sequencing Identified a Novel Variant (C.405_422+39del) in DSP Gene in an Iranian Pedigree with Familial Dilated Cardiomyopathy.

BACKGROUND: Dilated cardiomyopathy (DCM) is a progressive heart condition characterized by left ventricular chamber enlargement associated with systolic heart failure and prolonged action potential duration. Genetic variations in genes that encode cytoskeleton, sarcomere, and nuclear envelope proteins are responsible for 45% of cases. In our study, we focused on a pedigree with familial DCM to decipher the potential genetic cause(s) in affected members developing arrhythmia, end-stage heart failure, and sudden death. METHODS: Whole-exome sequencing (WES) was exploited for a 27-year-old heart-transplanted female as the proband, and the derived data were filtered using the standard pipelines. RESULTS: A 57-nucleotide deletion (c.405_422+39del) in the desmoplakin gene (DSP) (NM_004415.4) was identified as a novel pathogenic variant. Familial segregation analysis indicated that this variant is present in clinically affected members and absent in unaffected members. CONCLUSION: It seems that the detected variant induces intron retention, resulting in a premature stop codon in intron 3 of DSP leading to production of a truncated, nonfunctional protein. Additionally, it can trigger a nonsense-mediated mRNA decay pathway associated with inhibition of protein production. The present study results illustrated that a novel deletion in DSP can cause DCM in an Iranian family.

Expression and Clinicopathological Significances of lncRNAs: Could ARA and ZEB2NAT be the Potential Breast Cancer-Related Biomarkers?

INTRODUCTION: Pieces of evidence have shown that a significant proportion of cancer-prone factors are not attributed to alterations in protein-coding sequences. Adriamycin resistance-related (ARA) and natural antisense of ZEB2 (ZEB2NAT) long non-coding RNAs (lncRNAs) have been indicated with oncogenic properties by regulating various signaling pathways and epithelial-to-mesenchymal transition (EMT), which may have diagnostic and prognostic potential as a novel group of biomarkers. AIM: The current study aimed to evaluate the expression status of ARA and ZEB2NAT lncRNAs and their clinicopathological significance in a population with breast cancer (BC). METHODS: Total RNA was extracted from 60 tumor samples and their normal adjacent tissues (NATs). The lncRNA expressions were measured using quantitative reverse transcription PCR (RT-qPCR) and statistical analyses were performed by SPSS version 25. RESULTS: Our data showed a significant upregulation of ARA and ZEB2NAT lncRNAs in tumor tissues compared to NATs (p <0.001; p = 0.021, respectively). ARA and ZEB2NAT expression were observed to be significantly associated with tumor grade, nuclear grade, tumor stages, and lymph node metastasis (p <0.05). Additionally, ARA expression was significantly correlated with breastfeeding status (p = 0.027). CONCLUSION: our data revealed that ARA and ZEB2NAT lncRNAs were overexpressed in BC. Furthermore, the selected lncRNAs were found to might be the potential biomarkers for BC diagnosis and prognosis. However, the findings of the current research are required to be replicated in other studies with larger sample sizes.

CRB1-Related Leber Congenital Amaurosis: Reporting Novel Pathogenic Variants and a Brief Review on Mutations Spectrum

Background: LLeber congenital amaurosis (LCA) is a rare inherited retinal disease causing severe visual impairment in infancy. It has been reported that 9-15% of LCA cases have mutations in CRB1 gene. The complex of CRB1 protein with other associated proteins affects the determination of cell polarity, orientation, and morphogenesis of photoreceptors. Here, we report three novel pathogenic variants in CRB1 gene and then briefly review the types, prevalence, and correlation of reported mutations in CRB1 gene. Methods: Whole exome sequencing and targeted gene panel were employed. Then validation in the patient and segregation analysis in affected and unaffected members was performed. Results: Our detected novel pathogenic variants (p.Glu703*, c.2128+1G>A and p.Ser758SerfsX33) in CRB1 gene were validated by Sanger sequencing. Segregation analysis confirmed the inheritance pattern of the pathogenic variants. Conclusion: Our findings show that emerging the next-generation sequencing-based techniques is very efficient in identifying causative variants in disorders with locus heterogeneity.

Disturbed Th1 and Th2 balance in patients with Graves' disease.

BACKGROUND AND METHODS: Graves' disease (GD) is a common autoimmune disorder that is primarily driven by malfunction of T lymphocytes, which influences the production of antibodies reacting with cellular and tissue components of the thyroid gland. The aim of this study was to determine the level of mRNA expression for the genes encoding T-bet and GATA3, as the master regulators of the T helper (Th)1 and Th2 differentiation, respectively together with Th1 (IFN-γ) and Th2(IL-4) cytokine mRNA expression. Relative quantification of T-bet, GATA3, IFN-γ and IL-4 transcripts in peripheral blood mononuclear cell (PBMCs) was conducted by real-time reverse transcriptase PCR (RT-PCR). Serum levels of IFN-γ and IL-4 were also determined by Enzyme-linked immunosorbent assay (ELISA). In comparison with the normal group, T-bet and IFN-γ mRNA expression levels were significantly up-regulated in the GD patients, while GATA3 and IL-4 mRNA expression levels were downregulated. In addition, a marked decrease in plasma IL-4 levels was observed in the GD group. IFN-γ levels were also higher in patients in comparison to the controls. Furthermore, a clear correlation between increased IFN-γ mRNA expression and IFN-γ (P<0.05) was revealed. These results indicate that a Th1/Th2 imbalance exists in GD, and it may be implicated in the pathogenesis of disease.