Clinical and molecular findings in a Turkish family with an ultra-rare condition, ELP2-related neurodevelopmental disorder

Novel biallelic nonsense mutation in IGHMBP2 gene linked to neuropathy (CMT2S): A comprehensive clinical, genetic and bioinformatic analysis of a Turkish patient with literature review

BACKGROUND

Spinal muscular atrophy with respiratory distress type 1 (SMARD1) and Charcot-Marie-Tooth type 2S (CMT2S) typically present before age 10. Genetic factors account for up to 50 % of neuropathies, which often display varied symptoms. Mutations in the IGHMBP2 gene are associated with both CMT2S and SMARD1, resulting in a rare clinical condition marked by axonal neuropathy, spinal muscular atrophy, respiratory distress, and muscle weakness.

METHOD

Detailed family histories and medical data were collected. Segregation analysis was performed using Sanger sequencing and whole exome sequencing. Additionally, a review of molecularly confirmed patients was conducted. Protein tertiary structures expressed in the IGHMBP2 gene were tested for topological and conformational changes using modeling programs and in-silico tools.

RESULTS

We identified a novel homozygous nonsense mutation (c.2568_2569del p.Gly857Alafs*27) in a family with a member showing neuropathy. This report details the clinical and genetic findings of the affected individuals, including a Turkish patient with neuropathy, and compares them with literature cases.

CONCLUSION

Understanding the clinical impact of the (c.2568_2569del p.Gly857Alafs*27) mutation will enhance our knowledge of IGHMBP2 gene defects role in neuropathy. This study aims to highlight this severe recessive disease caused by pathogenic IGHMBP2 gene mutations and to examine the mutation spectrum and phenotype differences.

Exploring cuproptosis-related molecular clusters and immunological characterization in ischemic stroke through machine learning

Objective

Ischemic stroke (IS) is a significant health concern with high disability and fatality rates despite available treatments. Immune cells and cuproptosis are associated with the onset and progression of IS. Investigating the interaction between cuproptosis-related genes (CURGs) and immune cells in IS can provide a theoretical basis for IS treatment.

Methods

We obtained IS datasets from the Gene Expression Omnibus (GEO) and employed machine learning to identify CURGs. The diagnostic efficiency of the CURGs was evaluated using receiver operating characteristic (ROC) curves. KEGG and gene set enrichment analysis (GSEA) were also conducted to identify biologically relevant pathways associated with CURGs in IS patients. Single-cell analysis was used to confirm the expression of 19 CURGs, and pathway activity calculations were performed using the AUCell package. Additionally, a risk prediction model for IS patients was developed, and core modules and hub genes related to IS were identified using weighted gene coexpression network analysis (WGCNA). We classified IS patients using a method of consensus clustering.

Results

We established a precise diagnostic model for IS. Enrichment analysis revealed major pathways, including oxidative phosphorylation, the NF-kappa B signaling pathway, the apoptosis pathway, and the Wnt signaling pathway. At the single-cell level, compared to those in non-IS samples, 19 CURGs were primarily overexpressed in the immune cells of IS samples and exhibited high activity in natural killer cell-mediated cytotoxicity, steroid hormone biosynthesis, and oxidative phosphorylation. Two clusters were obtained through consensus clustering. Notably, immune cell types including B cells, plasma cells, and resting NK cells, varied between the two clusters. Furthermore, the red module and hub genes associated with IS were uncovered. The expression patterns of CURGs varied over time.

Conclusion

This study developed a precise diagnostic model for IS by identifying CURGs and evaluating their interaction with immune cells. Enrichment analyses revealed key pathways involved in IS, and single-cell analysis confirmed CURG overexpression in immune cells. A risk prediction model and core modules associated with IS were also identified.

Apoptosis-associated speck-like protein containing a CARD (ASC), TNF Like Factor 1a(TL-1a) and B Cell Chemoattractant Chemokine Ligand 13(CXCL-13) expression profiles in familial Mediterranean fever (FMF) patients

Objectives: This study was carried out to compare the expression levels of ASC(Apoptosis Associated Speck Like Protein Containing a CARD), TL-1a(TNF Like Factor 1a) and CXCL 13(B Cell Chemoattractant Chemokine Ligand 13) genes in FMF patients According to Tell-Hashomer Criteria and Genetic analysis result in Düzce University Research and Application Hospital with healthy controls and to determine their clinical significance in FMF. Method: 36 patients (20 girls, 16 boys) and 12 healthy controls (7 girls, 5 boys) were included in the study. RNA was isolated from the peripheral blood of each individual and expression levels of ASC, TL-1a and CXCL 13 genes were determined. Routine biochemical parameters were also determined. Result: CXCL 13 and TL-1a gene expression levels were significantly increased in patients with FMF, the expression level of the ASC gene was found to be increased in FMF patients, but not significantly. Conclusion: The expression levels of these genes may be related to the pathogenesis of the disease and these genes could be used as a marker in the early diagnosis of the disease.

Epilepsy or neurodevelopmental disorders are associated with homozygous and pathogenic ELP2 variation in three siblings

Developmental and Epileptic Encephalopathies (DEEs) are a group of early-onset syndromic disorders characterized by varying degree of intellectual disability, autism spectrum, seizures, and developmental delay. Herein, we have clinically and genetically dissected three siblings from Turkey with DEE born to first cousin unaffected parents. We identified a homozygous pathogenic variant in ELP2 (ENST00000358232.11:c.1385G>A; p.(Arg462Gln)). Our results, together with in depth literature review, underlie the importance of codon encoding the arginine at position 462 as a hotspot for ELP2 related neurological phenotypes.

ELP2 compound heterozygous variants associated with cortico-cerebellar atrophy, nodular heterotopia and epilepsy: Phenotype expansion and review of the literature

The elongator complex is a highly conserved macromolecular assembly composed by 6 individual proteins (Elp 1-6) and it is essential for many cellular functions such as transcription elongation, histone acetylation and tRNA modification. ELP2 is the second major subunit and with Elp1 and Elp3 it shapes the catalytic core of this essential complex. ELP2 gene pathogenic variants have been reported to be associated with several neurodevelopmental disorders, such as intellectual disability, severe motor development delay with truncal hypotonia, spastic diplegia, choreoathetosis, short stature and neuropsychiatric problems. Here we report a case with heterozygous variants of the ELP2 gene associated with unpublished electro-clinical and neuroimaging features, such as abnormal eye movements, focal epilepsy, cortico-cerebellar atrophy and nodular cortical heterotopia on brain MRI. A possible phenotype-genotype correlation and the electro-clinical and neuroimaging phenotype expansion of ELP2 mutations are here discussed, together with considerations on involved cortico-cerebellar networks and a detailed review of the literature.