Publications by authors named "Amel Haj Khelil"

Background: ​Vascular endothelial growth factor A (VEGFA) is well acknowledged as a powerful angiogenesis-promoting agent mainly through its receptor VEGFR2. Ischemia stimulates VEGFA/VEGFR2 signaling pathway and elevated serum levels of VEGFA were detected in coronary heart disease (CHD) patients. The goal of the current study is to determine how four SNPs in the genes for VEGFA (rs3025039 and rs699947) and VEGFR2 (rs2305948 and rs1870377) contribute to the development of CHD.

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Psychomotor delay, epilepsy and dysmorphic features are clinical signs which are described in multiple syndromes due to chromosomal imbalances or mutations involving key genes implicated in the stages of Early Embryonic Development. In this context, we report a 10 years old Tunisian patient with these three signs. Our objective is to determine the cause of developmental, behavioral and facial abnormalities in this patient.

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Article Synopsis
  • Coronary artery disease (CAD) can lead to myocardial infarction (MI), which increases the risk of sudden cardiac death (SCD) and ventricular arrhythmias (VA).
  • The study aimed to link specific genetic variations (SNPs) in genes related to heart arrhythmias with the likelihood of developing VA during an MI.
  • Results indicated that two SNPs, specifically in the SCN5A and SCN10A genes, were significantly connected to a higher risk of VA in MI patients, which could potentially help in predicting and preventing SCD.
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Background: Brugada syndrome (BrS) is a rare inherited cardiac arrhythmia associated with a high risk of sudden cardiac death (SCD) due to ventricular fibrillation (VF). BrS is characterized by coved-type ST-segment elevation in the right precordial leads (V1-V3). Mutations in SCN5A gene coding for the α-subunit of the NaV1.

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Over the past few years, studies of DNA isolated from human fossils and archaeological remains have generated considerable novel insight into the history of our species. Several landmark papers have described the genomes of ancient humans across West Eurasia, demonstrating the presence of large-scale, dynamic population movements over the last 10,000 years, such that ancestry across present-day populations is likely to be a mixture of several ancient groups [1-7]. While these efforts are bringing the details of West Eurasian prehistory into increasing focus, studies aimed at understanding the processes behind the generation of the current West Eurasian genetic landscape have been limited by the number of populations sampled or have been either too regional or global in their outlook [8-11].

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Brugada syndrome (BrS) is an autosomal-dominant genetic cardiac disorder caused in 18-30 % of the cases by SCN5A gene mutations and manifested by an atypical right bundle block pattern with ST segment elevation and T wave inversion in the right precordial leads. The syndrome is usually detected after puberty. The identification of BrS in pediatric patients is thus a rare occurrence, and most of the reported cases are unmasked after febrile episodes.

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Background: The human cardiac action potential in atrial and ventricular cells is initiated by a fast-activating, fast-inactivating sodium current generated by the SCN5A/Nav1.5 channel in association with its β1/SCN1B subunit. The role of Nav1.

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Background: Primary distal renal tubular acidosis (dRTA) caused by mutations in the genes that codify for the H + -ATPase pump subunits is a heterogeneous disease with a poor phenotype-genotype correlation. Up to now, large cohorts of dRTA Tunisian patients have not been analyzed, and molecular defects may differ from those described in other ethnicities. We aim to identify molecular defects present in the ATP6V1B1, ATP6V0A4 and SLC4A1 genes in a Tunisian cohort, according to the following algorithm: first, ATP6V1B1 gene analysis in dRTA patients with sensorineural hearing loss (SNHL) or unknown hearing status.

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Background: Myocardial infarction (MI) is a major clinical problem because of its large contribution to mortality. The genetic bases of this disease have been widely studied in recent years to find a clear association with some genetic markers that increase the risk of its occurrence. In the present investigation, the correlation between MI and the C3 complement polymorphism was analyzed using a case-control study.

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It is generally agreed that the protease inhibitor (PI) alleles PI*S (Val264Glu) and PI*Z (Lys342Glu) are the most common alpha 1 antitrypsin deficiency variants worldwide, but the PI*Mmalton allele (ΔPhe52) prevails over these variants in some Mediterranean regions. In eastern Tunisia (Mahdia), we screened 100 subjects with chronic obstructive pulmonary disease for these variants. The PI*S and PI*Z alleles were genotyped by the previously described SexAI/Hpγ99I RFLP-PCR.

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There is substantial evidence found in the literature that supports the fact that the presence of oxidative stress may play an important role in the pathophysiology of schizophrenia. The glutathione S-transferases (GSTs) forms one of the major detoxifying groups of enzymes responsible for eliminating products of oxidative stress. Interindividual differences observed in the metabolism of xenobiotics have been attributed to the genetic polymorphism of genes coding for enzymes involved in detoxification.

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Unlabelled: Few data regarding molecular diagnosis of primary distal renal tubular acidosis (DRTA) in Tunisian population are available.

Case Report: 25-day-old male patient from consanguineous parents of Tunisian origin diagnosed with DRTA and without hearing impairment observed later in life. ATP6V0A4 gene sequencing demonstrated a novel homozygous G deletion in exon 13 (c.

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Smoking is considered as the major causal factor of chronic obstructive pulmonary disease (COPD). Nevertheless, a minority of chronic heavy cigarette smokers develops COPD. This suggests important contribution of other factors such as genetic predisposing.

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Chronic obstructive pulmonary disease (COPD) is characterized by systemic and local chronic inflammation and oxidative stress. The sources of the increased oxidative stress in COPD patients derive from the increased burden of inhaled oxidants such as cigarette smoke and other forms of particulate or gaseous air pollution and from the increase in reactive oxygen species (ROS) generated by several inflammatory, immune, and structural airways cells. There is increasing evidence that genetic factors may also contribute to the pathogenesis if COPD, particularly antioxidant genes, which may confer a susceptibility to environmental insults such as cigarette smoke and thereafter development of COPD.

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Alpha1-antitrypsin (AAT) is a highly polymorphic protein with more than 120 variants that are classified as normal (normal protein secretion), deficient (reduced circulating AAT level caused by defective secretion) or null (no protein secretion). Alpha1-antitrypsin deficiency, one of the most common genetic disorders, predisposes adults to pulmonary emphysema and, to a lesser extent, chronic liver disease and cirrhosis. In this report, we provide additional sequence data for alpha1-antitrypsin based on the characterization of a novel variant detected in a 53-year-old heterozygous patient with chronic obstructive pulmonary disease.

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This study was undertaken to ascertain if a relationship existed between oxidative status and polymorphisms of microsomal epoxide hydrolase X1 (EPHX1), glutathione S-transferase P1 (GSTP1), GSTM1, and GSTT1 in chronic obstructive pulmonary disease (COPD). Erythrocyte glutathione peroxidase (GSH-px), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), and plasma GST activities and total antioxidant status (TAS) as antioxidative stress markers were determined and compared either with individual and combined genotypes of EPHX1 exon 3, GSTP1 exon 5, GSTM1, and GSTT1 polymorphisms in COPD patients and healthy controls from the central area of Tunisia. Statistical data processing revealed significantly lower GSH-px, GR, SOD, CAT, GST, and TAS values in COPD patients in comparison to the control group (P < .

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The -158 (C→T) nucleotide change, known as Xmn I polymorphism, occurs in (G)γ-globin gene promoter, and results in elevated fetal hemoglobin (HbF). We found this mutation in cis of a β(0)-thalassemia splicing mutation. Despite the complete absence of adult HbA, the phenotype was only moderately severe with no detectable alteration of α-globin gene expression.

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It is well known that cigarette smoking is the major risk factor for chronic obstructive pulmonary disease (COPD). However, only 10%-20% of chronic heavy cigarette smokers develop symptomatic disease, which suggests the presence of genetic susceptibility. Microsomal epoxide hydrolase (EPHX1) is an enzyme involved in the protective mechanism against oxidative stress.

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Background: Hemolytic uremic syndrome consists of a triad of acquired hemolytic anemia, thrombocytopenia and renal failure.

Aim: Our objectives were to determine epidemiology, clinical and laboratory characteristics of patients with atypical hemolytic uremic syndrome (aHUS) to determine the relationship between the complement protein deficit and aHUS in the Tunisian population.

Methods: We studied retrospectively four cases of atypical HUS in adults admitted in the Nephrology Department of Fattouma Bourguiba Universitary Hospital in Monastir between 2000 and 2008.

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GSTM1 and GSTT1 polymorphisms have been proposed in relationship with chronic obstructive pulmonary disease (COPD). We investigated the association between these polymorphisms and COPD (as well as its subtypes emphysema and chronic bronchitis) in 234 COPD patients and 182 healthy controls in the Tunisian population. Genotyping was performed using multiplex PCR.

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Hemolytic anemias are very common diseases. Among these diseases, hemoglobinopathies are widely spread throughout the Mediterranean Basin, including North Africa (Tunisia, Algeria and Morocco). Their severity and disabling nature make them a major public health problem.

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Alpha 1 antitrypsin deficiency (AATD) is a well recognized genetic risk factor for pulmonary disease and less common liver disease. The two most common deficiency alleles worldwide PI*S and PI*Z can be easily detected using several molecular methods. However, there are at least 30 other AATD variants, which are only detectable by alpha 1 antitrypsin (AAT) gene sequencing and, therefore, seem to be more under-recognized than the PI*S and PI*Z alleles.

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Alpha-1-antitrypsin (AAT) plays an important role in the pathogenesis of emphysema, the pathological lesion underlying the majority of the manifestations of Chronic Obstructive Pulmonary Disease (COPD). In this study we tested the hypothesis that common AAT polymorphisms influence the risk of developing COPDs. We investigated PiM1 (Ala213Val), PiM2 (Arg101His), PiM3 (Glu376Asp), PiS (Glu264Val) and PiZ (Glu342Lys) SERPINA1 alleles in 100 COPD patients and 200 healthy controls.

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