Exome sequencing identifies a novel mutation of the GDI1 gene in a Chinese non-syndromic X-linked intellectual disability family

Genetic heterogeneity in epilepsy and comorbidities: insights from Pakistani families

BACKGROUND

Epilepsy, a challenging neurological condition, is often present with comorbidities that significantly impact diagnosis and management. In the Pakistani population, where financial limitations and geographical challenges hinder access to advanced diagnostic methods, understanding the genetic underpinnings of epilepsy and its associated conditions becomes crucial.

METHODS

This study investigated four distinct Pakistani families, each presenting with epilepsy and a spectrum of comorbidities, using a combination of whole exome sequencing (WES) and Sanger sequencing. The epileptic patients were prescribed multiple antiseizure medications (ASMs), yet their seizures persist, indicating the challenging nature of ASM-resistant epilepsy.

RESULTS

Identified genetic variants contributed to a diverse range of clinical phenotypes. In the family 1, which presented with epilepsy, developmental delay (DD), sleep disturbance, and aggressive behavior, a homozygous splice site variant, c.1339-6 C > T, in the COL18A1 gene was detected. The family 2 exhibited epilepsy, intellectual disability (ID), DD, and anxiety phenotypes, a homozygous missense variant, c.344T > A (p. Val115Glu), in the UFSP2 gene was identified. In family 3, which displayed epilepsy, ataxia, ID, DD, and speech impediment, a novel homozygous frameshift variant, c.1926_1941del (p. Tyr643MetfsX2), in the ZFYVE26 gene was found. Lastly, family 4 was presented with epilepsy, ID, DD, deafness, drooling, speech impediment, hypotonia, and a weak cry. A homozygous missense variant, c.1208 C > A (p. Ala403Glu), in the ATP13A2 gene was identified.

CONCLUSION

This study highlights the genetic heterogeneity in ASM-resistant epilepsy and comorbidities among Pakistani families, emphasizing the importance of genotype-phenotype correlation and the necessity for expanded genetic testing in complex clinical cases.

GDP dissociation inhibitor 1 (GDI1) attenuates β-amyloid-induced neurotoxicity in Alzheimer's diseases

OBJECTIVE

β-Amyloid (Aβ) induced neurotoxicity is an implicated mechanism in Alzheimer's disease (AD). This study focused on the role of GDP dissociation inhibitor 1 (GDI1) in Aβ-induced neurotoxicity.

METHODS

Data from the GEO database for AD-related datasets GSE140829, GSE63061, GSE36980, and GSE60360 were downloaded and identified common differentially expressed genes (coDEGs). The mRNA levels of GDI1 in the serum of AD patients were analyzed by RT-qPCR. ROC curve evaluated the diagnostic value. Aβ25-35 induced SH-SY5Y cells to construct an AD cell model. CCK-8, flow cytometry, and ELISA assay were used to analyze cell viability, apoptosis, and concentrations of inflammatory factors. KEGG enrichment was employed to analyze the signal pathway of targets from GDI1 in the AD.

RESULTS

The GEO database identifies coDEGs including GDI1. GDI1 is generally elevated in serum from AD patients as well as in Aβ-induced SH-SY5Y cells. GDI1 has 77.97% sensitivity and 84.44% specificity to identify AD patients from controls. Aβ induced decreased cell viability, increased apoptosis, and promoted over-secretion of inflammatory cytokines, but they were all partially weakened by reduced GDI1. What's more, the GDI1 interacting gene and AD target gene were co-enriched on Endocytosis and MAPK signaling pathway.

CONCLUSION

Elevated GDI1 is a potential diagnostic biomarker for AD and that inhibition of GDI1 attenuates Aβ-induced neurotoxicity in AD. Our study offers new horizons for AD treatment.

Mutations in the COL18A1 gen associated with knobloch syndrome and structural brain anomalies: a novel case report and literature review of neuroimaging findings

. COL18A1 gene mutations have been associated with Knobloch syndrome, which is characterized by ocular and brain abnormalities. Here we report a 4.5 years-old male child with autism and two novel COL18A1 mutations (NM_030582.4: c.1883_1891dup and c.1787C>T). Hypermetropic astigmatism, but not brain migration disorders, was observed. However, an asymmetric pattern of cerebellar perfusion and a smaller arcuate fascicle were found.  Low levels of collagen XVIII were also observed in the patient´s serum. Thus, biallelic loss-of-function mutations in COL18A1 may be a new cause of autism  without the brain malformations typically reported in patients with Knobloch syndrome.

Overexpression of GDP dissociation inhibitor 1 gene associates with the invasiveness and poor outcomes of colorectal cancer

GDP dissociation inhibitor (GDI) regulates the GDP/GTP exchange reaction of most Rab proteins by inhibiting GDP dissociation. This study evaluated the potential prognostic and predictive value of GDI1 in colorectal cancer (CRC). To address the prognostic power of GDI1, we performed individual and pooled survival analyses on six independent CRC microarray gene expression datasets. GDI1-enriched signatures were also analyzed. Kaplan-Meier and Cox proportional analyses were employed for survival analysis. An immunohistochemistry (IHC) analysis was performed to validate the clinical relevance and prognostic significance of the GDI1 protein level in CRC tissue samples. The results revealed that GDI1 mRNA level was significantly linked with the aggressiveness of CRC, which is compatible with gene set enrichment analysis. A meta-analysis and pooled analysis demonstrated that a higher mRNA GDI1 expression was dramatically correlated with a worse survival in a dose-dependent manner in CRC patients. Further IHC analysis validated that the protein expression of GDI1 in both cytoplasm and membrane also significantly impacted the outcome of CRC patients. In CRC patients with stage III, chemotherapy significantly reduced the relative risk of death in low-GDI1 subgroup (hazard ratio (HR) = 0.22; 95% confidence interval (95% CI) 0.09-0.56, p = 0.0003), but not in high-GDI1 subgroup (HR = 0.63; 95% CI 0.35-1.14, p = 0.1137). Therefore, both high mRNA and protein levels of GDI1 were significantly related to poor outcomes in CRC patients. GD11 may serve as a prognostic biomarker for CRC.