CRISPR/Cas9 genome editing for neurodegenerative diseases.

Gene therapy has emerged as a promising therapeutic strategy for various conditions, including blood disorders, ocular disease, cancer, and nervous system disorders. The advent of gene editing techniques has facilitated the ability of researchers to specifically target and modify the eukaryotic cell genome, making it a valuable tool for gene therapy. This can be performed through either in vivo or ex vivo approaches. Gene editing tools, such as zinc finger nucleases, transcription activator-like effector nucleases, and CRISPR-Cas-associated nucleases, can be employed for gene therapy purposes. Among these tools, CRISPR-Cas-based gene editing stands out because of its ability to introduce heritable genome changes by designing short guide RNAs. This review aims to provide an overview of CRISPR-Cas technology and summarizes the latest research on the application of CRISPR/Cas9 genome editing technology for the treatment of the most prevalent neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, Huntington's disease, Amyotrophic lateral sclerosis, and Spinocerebellar ataxia.

Homozygous mutation in CSF1R causes brain abnormalities, neurodegeneration, and dysosteosclerosis (BANDDOS).

Introduction: The CSF1R gene encodes the receptor for colony-stimulating factor-1, the macrophage, and monocyte-specific growth factor. Mutations in this gene cause hereditary diffuse leukoencephalopathy with spheroids (HDLS) with autosomal dominant inheritance and BANDDOS (Brain Abnormalities, Neurodegeneration, and Dysosteosclerosis) with autosomal recessive inheritance. Methods: Targeted gene sequencing was performed on the genomic DNA samples of the deceased patient and a fetus along with ten healthy members of his family to identify the disease-causing mutation. Bioinformatics tools were used to study the mutation effect on protein function and structure. To predict the effect of the mutation on the protein, various bioinformatics tools were applied. Results: A novel homozygous variant was identified in the gene CSF1R, c.2498C>T; p.T833M in exon 19, in the index patient and the fetus. Furthermore, some family members were heterozygous for this variant, while they had not any symptoms of the disease. In silico analysis indicated this variant has a detrimental effect on CSF1R. It is conserved among humans and other similar species. The variant is located within the functionally essential PTK domain of the receptor. However, no structural damage was introduced by this substitution. Conclusion: In conclusion, regarding the inheritance pattern in the family and clinical manifestations in the index patient, we propose that the mentioned variant in the CSF1R gene may cause BANDDOS.

A novel missense variant in ESRRB gene causing autosomal recessive non-syndromic hearing loss: in silico analysis of a case.

BACKGROUND: Hereditary hearing loss (HHL) is a common heterogeneous disorder affecting all ages, ethnicities, and genders. The most common form of HHL is autosomal recessive non-syndromic hearing loss (ARNSHL), in which there is no genotype-phenotype correlation in the majority of cases. This study aimed to identify the genetic causes of hearing loss (HL) in a family with Iranian Azeri Turkish ethnicity negative for gap junction beta-2 (GJB2), gap junction beta-6 (GJB6), and mitochondrially encoded 12S rRNA (MT-RNR1) deleterious mutations. METHODS: Targeted genome sequencing method was applied to detect genetic causes of HL in the family. Sanger sequencing was employed to verify the segregation of the variant. Finally, we used bioinformatics tools and American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines to determine whether the detected variant might affect the corresponding protein or not. RESULTS: A novel homozygous missense mutation, c.499G>A (p.G167R), was identified in exon 5 of the ESRRB (estrogen-related receptor beta) gene. Healthy and affected family members confirmed the co-segregation of the variant with ARNSHL. Eventually, the variant's pathogenicity was confirmed by the in silico analysis and the ACMG/AMP guidelines. CONCLUSION: The study suggests that the detected variant, c.499G>A, plays a crucial role in the development of ARNSHL, emphasizing the clinical significance of the ESRRB gene in ARNSHL patients. Additionally, it would be helpful for genetic counseling and clinical management of ARNSHL patients and providing preventive opportunities.

A new report of autoinflammation and PLCG2-associated antibody deficiency and immune dysregulation (APLAID) with a homozygous pattern from Iran.

Autoinflammation and PLCG2-associated antibody deficiency and immune dysregulation (APLAID) is an autosomal dominant autoinflammatory disease characterized by episodic skin, musculoskeletal, ophthalmic and gastrointestinal tract symptoms. Here we report an 11-year-old girl with a history of repeated episodes of fever, myalgia, arthralgia, abdominal pain, and urticarial rash in the trunk and limbs. Chest and pelvic X-Ray, sacroiliac joints MRI, brain MRI and abdominal CT scan were normal. Anti-nuclear antibody, Rheumatoid factor, cryoglobulin, ANCA/PR3, p-ANCA/MPO, anti-smooth muscle antibody and anti-mitochondrial antibody were negative. Serology for cytomegalovirus, Epstein-Barr, hepatitis B, hepatitis C, and HIV viruses was negative. Serum immunoglobulins were in the normal range. Genetic analysis for familial Mediterranean fever syndrome was negative. Whole exome sequencing was carried out to identify the genetic cause of our patient. We identified a homozygous missense variant (c.579C > G, p. His193Gln) in exon 7 of the PLCG2 gene. Bioinformatic analysis and clinical symptoms suggests this variant to be pathogenic in the homozygous state for APLAID and thus probably acting in an autosomal recessive manner. Our bioinformatic analysis also showed this novel mutation to have detrimental effects on the 3D structure of the PLCG2 protein, which is well conserved among many other similar species.

Evaluation of microsatellite instability in tumor and tumor marginal samples of sporadic colorectal cancer using mononucleotide markers.

Microsatellite instability (MSI) is a unique molecular alteration that is due to a defective DNA mismatch repair (MMR) system. Approximately, 15-20 % of sporadic colorectal cancers (CRC) display MSI. Determination of MSI status in CRC has prognostic and predictive implications. Additionally, detecting MSI is used diagnostically for tumor detection and classification. The present study analyzed a panel of five mononucleotide markers, BAT-25, BAT-26, NR-21, NR-22 and NR-27, amplified in a single multiplex PCR reaction to evaluate MSI status in CRC patients. Genomic DNA from 50 CRC and paired adjacent normal tissues was used for PCR-based MSI analysis. Our finding showed microsatellite instability in 36 % of specimens. Instability with differences in allele lengths was observed in the tumoral DNA compared to the tumor-free margin DNA sample. The frequency of instability in NR-21, BAT-26 and BAT-25 markers were more than others; their frequency were 35.48 %, 29.03 %, and 22.58 %, respectively. In conclusion, the NR-21, BAT-26, and BAT-25 were the most useful markers for discriminating cancer tissue from normal, therefore these markers have demonstrated promising potential for determining MSI status in patients with sporadic colorectal cancer.