Biomedical subjects

Saoussen Chouchene

Publications and source records attributed to Saoussen Chouchene.

3 recordsLinked to original sources

PubMed2026

Analysis of genetic polymorphisms and mRNA expression of DRD3 and HTR2A in bruxism.

BACKGROUND: Bruxism, characterized by the involuntary grinding or clenching of teeth, is influenced by genetic, psychological, and environmental factors. This study aimed to evaluate the role of DRD3 (rs6280) and HTR2A (rs6313) polymorphisms in bruxism and to investigate the expression of these genes to better understand their biological significance. METHODS: This case-control study included 82 bruxism patients and 87 controls. Diagnosis was based on clinical examination and non-instrumental criteria from the 2018 international consensus. Genotyping of HTR2A rs6313 and DRD3 rs6280 was performed using PCR-RFLP, and gene expression in peripheral blood was assessed by qPCR. Statistical analyses included chi-square tests, logistic regression, and mRNA expression analysis using the ΔΔCt method. RESULTS: A significant association was identified between bruxism and the rs6313 polymorphism of the HTR2A gene (p = 0.004; OR = 1.89 [1.23-2.92]), with the C allele associated with increased risk. Moreover, HTR2A mRNA expression was upregulated in individuals with bruxism. While no significant differences were observed in DRD3 rs6280 genotype distribution between cases and controls, the presence of the C allele appeared to increase susceptibility to sleep bruxism. In addition, DRD3 mRNA expression was downregulated in bruxism patients. CONCLUSIONS: These findings highlight a significant association between bruxism and the rs6313 polymorphism of the HTR2A gene. Furthermore, increased HTR2A and decreased DRD3 expression support the involvement of serotonin and dopamine pathways in bruxism etiology, underscoring its multifactorial and complex nature. CLINICAL SIGNIFICANCE: This study elucidates the genetic basis of bruxism, indicating a potential role of serotonin and dopamine signaling in its pathogenesis. Understanding genetic predisposition could aid in early detection, risk assessment, and targeted treatment development. TRIAL REGISTRATION: Clinicaltrials.gov ; trial registration number: NCT06457646 (13/06/2024).

Adult↗

PubMed2025

Association of Cyp2c19 Genotype with Variability in Clopidogrel Response in Coronary Patients.

The variability of clopidogrel response is due to many factors including polymorphisms affecting CYP2C19. This study aims to assess the impact of the CYP2C19*2(681G > A), CYP2C19*3(636G > A) and CYP2C19*17(-806 C > T) polymorphisms on platelet response to clopidogrel in patients with coronary artery disease. This is a cross-sectional study led on patients treated with clopidogrel (75 mg/day for at least seven days). Platelet reactivity was assessed by the VerifyNow® P2Y12 test and high on treatment platelet reactivity was defined by a PRU ≥ 208. The genotyping of CYP2C19 polymorphisms was performed by PCR- RFLP. The study involved 115 coronary patients with a mean age of 58 ± 10 years. The VerifyNow®P2Y12 test showed that 27.8% were resistant to clopidogrel. The genetic study showed that CYP2C19*2(681G > A) is significantly associated with biological resistance to clopidogrel (G vs. A, OR = 4.713 [95% CI: 1.738-12.780]; p = 0.002), while CYP2C19*17(-806 C > T) is a protective factor against clopidogrel non-responsiveness (C vs. T, OR = 0.413 [95% CI: 0.174-0.981]; p = 0.02). By classifying patients into extensive (*1/*1: 52%), intermediate (*1/*2: 16%) and ultra-rapid metabolizers (*1/*17;*17/*17: 32%), we found that the type of metabolizer had a significant impact on clopidogrel response (p = 0.001). CYP2C19*2 (681G > A) is significantly associated with biological resistance to clopidogrel while CYP2C19*17(-806 C > T) is a protective factor against clopidogrel non-responsiveness.

Cardiovascular↗

PubMed2025

Comprehensive analysis of a novel LYST mutation in a Tunisian patient with Chediak-Higashi syndrome.

BACKGROUND: Chediak-Higashi Syndrome (CHS) is a rare autosomal recessive disorder characterized by oculocutaneous albinism, recurrent infections, bleeding tendencies, and progressive neurological impairment. The syndrome is caused by mutations in the LYST gene, which plays a crucial role in lysosomal trafficking. OBJECTIVE: This study aims to characterize the molecular basis of CHS in a Tunisian patient by identifying mutations in the LYST gene and analyzing their impact on the protein function, correlating these findings with the patient's clinical presentation. METHODS: A comprehensive clinical assessment was conducted on the patient, followed by biochemical, hematological, and microbiological analyses. Additionally, LYST protein levels were quantified in the patient and their parents using an ELISA assay. Genomic DNA was extracted from the patient's blood, and Whole Exome Sequencing (WES) was performed to identify mutations in the LYST gene. The findings were confirmed through Sanger sequencing, and bioinformatic tools were employed to predict the functional consequences of the detected mutations. RESULTS: The patient presented with classical symptoms of CHS, including silver hair, hypopigmented skin, recurrent infections, and neurological decline, with an unusually late onset at 18 years. ELISA results demonstrated significantly reduced LYST levels in the patient (1.8 ng/ml) compared to heterozygous parents (7.8 ng/ml and 8.1 ng/ml) and controls (9.2 ng/ml). Genetic analysis revealed a novel homozygous deletion, c.10269_10275del (p.Gly3424SerfsTer15), in the LYST gene, leading to a frameshift mutation and premature termination of the protein. Bioinformatic analysis demonstrated that this mutation leads to the deletion of five out of sven WD40 repeats in the protein's C-terminal region, which are critical for protein-protein interactions and lysosomal trafficking. CONCLUSION: The study identifies a novel LYST mutation in a Tunisian patient with CHS, expanding the spectrum of known genetic variants associated with the disease. The findings highlight the importance of genetic screening in populations with high consanguinity and underscore the need for targeted therapies to address the molecular defects in CHS.

Adolescent↗