Spectrum of Organic Aciduria Diseases in Tunisia: A 35-year Retrospective Study.

Background: Organic aciduria diseases (OADs) occur worldwide, with differences in prevalence and patterns between populations. Objectives: To describe the spectrum of OADs identified in Tunisia over a 35-years period. Materials and Methods: This retrospective study included patients who were diagnosed with OADs between 1987 and 2022 in the Laboratory of Biochemistry, Rabta Hospital, Tunisia. Organic acids were analyzed using gas chromatography-mass spectrometry. Results: A total of 30,670 urine samples were analyzed for OADs, of which 471 were positive for OADs. The estimated incidence of OADs in Tunisia was 6.78 per 100,000 live births. Methylmalonic (n = 146) and propionic (n = 90) acidurias were the most common OADs (estimated incidence: 2.10 and 1.30 per 100,000 live births, respectively). There were 54 cases of L-2-hydroxyglutatric acidurias and 30 cases of pyroglutamic acidurias, which makes it one of the highest in the world. The main clinical features were hypotonia (65%) and feeding difficulties (41%). Age at diagnosis was highly variable, ranging from 1 day to 49 years. Only 27% of the patients were diagnosed within the first month of life. The prevalence of OADs was highest in the Center-East and Southeast regions. Conclusions: In Tunisia, OADs are relatively frequent, but there are shortcomings regarding the diagnosis of these disorders. The frequency and health/social impact of these disorders warrant the need for implementing newborn screening programs and suitable patient management.

Single-center experience of congenital disorders of glycosylation syndrome screening in Tunisia: A retrospective study over a 15-year period (2007-2021).

BACKGROUND: We report the results gathered over 15 years of screening for congenital disorders of glycosylation syndrome (CDGS) in Tunisia according to clinical and biochemical characteristics. METHODS: Our laboratory received 1055 analysis requests from various departments and hospitals, for children with a clinical suspicion of CDGS. The screening was carried out through separation of transferrin isoforms by capillary zone electrophoresis. RESULTS: During the 15-year period, 23 patients were diagnosed with CDGS (19 patients with CDG-Ia, three patients with CDG-IIx, and one patient with CDG-X). These patients included 13 boys and 10 girls aged between 3 months and 13 years, comprising 2.18 % of the total 1055 patients screened. The incidence for CDGS was estimated to be 1:23,720 live births (4.21 per 100,000) in Tunisia. The main clinical symptoms related to clinical disease state in newborn and younger patients were psychomotor retardation (91 %), cerebellar atrophy (91 %), ataxia (61 %), strabismus (48 %), dysmorphic symptoms (52 %), retinitis pigmentosa, cataract (35 %), hypotonia (30 %), and other symptoms. CONCLUSION: In Tunisia, CDGS still remains underdiagnosed or misdiagnosed. The resemblance to other diseases, especially neurological disorders, and physicians' unawareness of the existence of these diseases are the main reasons for the underdiagnosis. In routine diagnostics, the screening for CDGS by biochemical tests is mandatory to complete the clinical diagnosis.

Analysis of Branched Amino Acids by UPLC as an Alternative Method for the Management of Patients with MUSD.

BACKGROUND: Maple syrup urine disease (MSUD) is a severe life-threatening metabolic disorder. Patients' poor outcomes could be prevented by early diagnosis and regular monitoring, which mainly depend on the analysis of branched amino acids (BCAAs) in plasma. The study aimed to test whether the analysis of BCAAs by ultra-performance liquid chromatography (UPLC) is an alternative to an analysis by ion-exchange chromatography (IEC) for the diagnosis and monitoring of MSUD. METHODS: The two methods analyzed fifty plasma samples obtained from treated and untreated patients with MSUD. Data were analyzed using Passing-Bablok and Bland-Altman methods. RESULTS: The slope of the regression lines was equal or close to one for the three BCAAs, indicating no significant proportional differences between the two methods. A slight positive or negative bias was found for leucine and alloisoleucine, respectively. However, for each amino acid, one or two measurement pairs were out of statistical interval of agreement. Despite small analytical differences, the two methods could be considered in clinical agreement since the differences have no impact on the diagnosis and management of patients. CONCLUSIONS: UPLC and IEC methods are in clinical agreement for plasma BCAAs analysis. The UPLC method could be used simultaneously or interchangeably with the IEC method for diagnosing and monitoring MSUD patients. However, for reasons of practicability, the alternative method should only be used when the usual method cannot be carried out.

Incidence of the Mucopolysaccharidoses in Tunisia, 1999 - 2021.

BACKGROUND: This cross-sectional study aimed to describe and discuss the epidemiology of mucopolysaccharidoses (MPS) in Tunisia. METHODS: Patients diagnosed with a MPS disorder in two referral laboratories in Tunisia between 1999 and 2021 were included. Diagnosis was based on clinical and radiological features and analysis of urinary glycosaminoglycans, and enzyme assay in some of the patients. RESULTS: Over the twenty-two years, 199 patients were diagnosed with MPS in Tunisia. The disorder was classified as MPS I, MPS II, MPS III, MPS IV, and MPS VI in 15.07%, 1.5%, 38.69%, 17.08% and 7.03% patients, respectively. Due to the lack of enzyme analysis, the disorder was classified as MPS I or II in 20.6% of patients, and no cases of MPS VII and IX were documented. Gender-ratio was 1.5 and age at diagnosis varied from 3 months to 18 years with a median of 46 months. Patients originated from across Tunisia, and no hotspot site was identified. During the survey period, 3,822,983 births occurred, which provides an estimated global incidence of MPS of 1:20,123 live births (4.97 per 100,000). MPS III was the most frequent type with an estimated incidence of 1.91 cases per 100,000 newborns. CONCLUSIONS: MPS disorders, especially MPS III are relatively frequent in Tunisia, likely due to a high rate of consanguineous marriages. Implementation of enzyme and genetic tests in Tunisia will allow diagnosis confirmation and subtype recognition, as well as accurate genetic counseling and prenatal diagnosis for MPS.

Matrix metalloproteinase 3 and 9 as genetic biomarkers for the occurrence of cardiovascular complications in coronary artery disease: a prospective cohort study.

BACKGROUND: Matrix metalloproteinases (MMPs) are widely expressed in atherosclerosis lesions. The disequilibrium of MMPs driving to an overexpression or a lack of its level can be influenced by genetic variations. MMP-3 and MMP-9 may be affected by specific polymorphisms like - 1612 5 A/6A and the - 1562 C/T respectively. We aim in the present study to investigate prospectively the association between the - 1612 5 A/6A MMP-3 and - 1562 C/T MMP-9 polymorphisms and clinical outcomes in patients with coronary artery disease (CAD). This study is elaborated to reveal whether one of these polymorphisms is a probable predictor of cardiovascular complications in this CAD cohort. METHODS AND RESULTS: A total of 168 patients with CAD were prospectively followed up over a period of 5 years. Genotypes for the MMP-3 (-1612 5 A/6A) and MMP-9 (-1562 C/T) polymorphisms were performed using PCR-RFLP. Their levels were measured by ELISA in Sandwich test during the follow-up period, 39 cardiovascular outcomes occurred with 21 repeat targets for revascularization, 3 patients with Myocardial infarction, 8 for heart failure, 5 for Stroke and 2 for cardiovascular mortality. The MMP-3 5 A/6A polymorphism was related to the disease on the contrary of the MMP-9 -1562 C/T. Patients carrying the 5 A allele had a higher level of MMP-3 level and those who carried the 6 A allele had lower level (p = 0.04). After applied multivariable Cox-hazard models we revealed that the 6 A allele is independently associated to the disease complication. Kaplan-Meier survival test revealed that individuals having the 6 A allele had a lower survival rate than those with the 5 A allele (p = 0.04). CONCLUSION: Our study suggests the disruption of the MMP-3 level may be due to the existence of the polymorphism - 1612 residing in its promoter region. MMP-3 can be considered as a marker of diagnosis and prediction in cardiovascular events.

Circulating MMP-7 and VEGF as potential predictive biomarkers for recurrent implantation failures.

Recurrent implantation failure (RIF) is considered to be one of the major limiting factors of assisted reproductive technology (ART) programme success. The current study focused on the investigation of matrix metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs), cytokines and cell adhesion molecules in peripheral blood (PB) and follicular fluid (FF) obtained from 44 women aged between 25 and 39 years old and undergoing intracytoplasmic sperm injection (ICSI). These women were divided into two groups: 22 RIF women with embryo implantation failures after the transfer of at least four fresh or frozen-thawed good quality embryos in a minimum of three ICSI cycles, and 22 ICSI success women (controls) who achieved a clinical pregnancy at their first ICSI attempt. The PB and FF samples were obtained from each patient on the day of oocyte retrieval. MMP-1, -2, -3, -7, -9, TIMP-1, -2, vascular endothelial growth factor (VEGF), leukaemia inhibitory factor (LIF), vascular cell adhesion molecule 1 (VCAM1) and intercellular adhesion molecules 1 (ICAM1) were analyzed using enzyme-linked immunosorbent assay of PB and FF. Our results showed significant decreases in PB MMP-7 and PB VEGF in the RIF group compared with controls [281.11 (33-614) pg/ml vs 119.92 (27-441) pg/ml; P-value = 0.030] and [82.54 (25.94-210.20) pg/ml vs 30.93 (13.62-193.33) pg/ml; P-value = 0.022; respectively]. Receiver operating characteristic (ROC) curve analysis showed informative area under the curve values for PB MMP-7, as well as for PB VEGF, making them able to be proposed as biomarkers of the RIF. Therefore, circulating MMP-7 and VEGF seem to play an interesting role in embryo implantation in in vitro fertilization (IVF)/ICSI cycles and could be proposed as circulating biomarkers of the RIF. These results could be helpful for clinicians and patients to choose the best rescue strategy and treatment to minimize implantation failure in women undergoing IVF/ICSI procedures after the first attempt.

Prognostic Significance of Plasma Folate and Cobalamin Concentrations in Non-Muscle-Invasive Bladder Cancer: A Prospective Cohort Study.

This cohort study aimed to investigate prognostic significance of plasma folate and cobalamin in non-muscle-invasive bladder cancer (NMIBC). A total of 177 NMIBC patients were followed over a period extending to 6 years. Cox regression models were applied to estimate risks for recurrence and progression according to plasma vitamins tertiles. Compared to first tertile, third tertile of plasma folate [HR (95% CI), 10.5 (1.32-83.4); p = 0.026] was associated, and of plasma cobalamin [2.12 (0.63-7.25); p = 0.116] tended to be associated with higher risk for progression. NIMBC patients with high folate/cobalamin statuses should make the physician more alert for a likely poor outcome.

Semen Creatine and Creatine Kinase Activity as an Indicator of Sperm Quality.

BACKGROUND: The role of creatine (Cr) and creatine kinase (CK) in sperm function remains unclear. The study aimed to assess Cr and CK in seminal plasma and test their association with sperm characteristics. METHODS: The study included 62 males with couple's infertility and 26 males who have already fathered children. Semen Cr and CK were assessed by GC-MS and spectrophotometry, respectively. Seminogram parameters were analyzed using conventional methods. RESULTS: Cytomorphologic analysis of sperm showed normozoospermia in 53 men (NS) and an asthenozoospermia (AS) in 35 men. Semen Cr was high with no significant difference between the two groups (791 ± 342 and 744 ± 422 µmol/L, respectively). However, semen CK activity was higher in AS group (1,360 ± 1,050 vs. 830 ± 580 U/L, p = 0.013). Semen Cr was positively related to progressive motility (r = 0.284; p = 0.010). Semen CK was negatively correlated with sperm concentration (r = -0.29; p = 0.01), progressive motility (r = -0.26; p = 0.03), and the percentage of abnormal spermatozoa (r = -0.28; p = 0.02). CONCLUSIONS: Semen contains high amounts of Cr and increased CK activity. Low semen Cr is associated with reduced sperm motility while high CK activity is associated with poor sperm quality. The findings suggest that Cr is of importance for sperm metabolism and that Cr supplementation could be useful in males with poor quality sperm.

Nonketotic Hyperglycinemia in Tunisia. Report upon a Series of 69 Patients.

AIM: The aim of the study is to report on epidemiological, clinical, and biochemical characteristics of nonketotic hyperglycinemia (NKH) in Tunisia. METHODS: Patients diagnosed with NKH in Laboratory of Biochemistry at Rabta hospital (Tunis, Tunisia) between 1999 and 2018 were included. Plasma and cerebrospinal fluid (CSF) free amino acids were assessed by ion exchange chromatography. Diagnosis was based on family history, patient's clinical presentation and course, and increased CSF to plasma glycine ratio. RESULTS: During 20 years, 69 patients were diagnosed with NKH, with 25 patients originating from Kairouan region. Estimated incidences were 1:55,641 in Tunisia and 1:9,684 in Kairouan. Consanguinity was found for 73.9% of the patients and 42% of the families have history of infantile death due to a disease of similar clinical course than the propositus. Clinical symptoms initiated within the first week of life in 75% of the patients and within the first 3 months in 95.7% ones. The phenotype was severe in 76.8% of the patients. Main symptoms were hypotonia, feeding difficulties, coma, apnea, and seizures. Most patients died within few days to months following diagnosis. CSF to plasma glycine ratio was increased in all patients. CSF and plasma glycine levels were negatively correlated with age of disease onset and severity. CONCLUSION: NKH is quite frequent in Tunisia. Kairouan region has the highest NKH incidence rate, worldwide. However, due to lack of confirmatory enzymatic and genetic tests, NKH diagnosis was based on first-line biochemical tests. Characterization of causal mutations is needed for accurate diagnosis and prenatal diagnosis of this devastating life-threatening disease.

Matrix metalloproteinase-7 could be a predictor for acute inflammation in psoriatic patients.

PURPOSE: The pathogenesis of psoriasis is characterized by a disruption of extracellular matrix (ECM) in which matrix metalloproteinases (MMPs) participate actively. We aimed to determine MMP-7 level and its association with the inflammatory response in order to determine its usefulness as a biomarker for psoriasis prediction. We also aimed to determine its distribution in uninvolved and involved psoriatic skin to evaluate the probable role of MMP-7 in psoriasis pathogenesis. MATERIALS AND METHODS: We recruited 108 psoriatic patients and 133 healthy controls. MMP-7, tissue inhibitors of metalloproteinases (TIMPs) and interleukin-6 (IL-6) levels were measured by Enzyme-Linked Immunosorbent Assay (ELISA) assay. MMP-7 expression was detected by Immunohistochemistry (IHC) study. RESULTS: ECM turnover and inflammatory biomarker levels were significantly higher in psoriatic patients. MMP-7 revealed to be independently associated to psoriasis even after adjustment for different models. The area under the curve (AUC) of MMP-7 and inflammation Z-score were similar. MMP-7 was positively correlated with IL-6 and inflammation Z-score. Psoriasis severity (PASI) was correlated significantly with IL-6 (p = 0.007). The MMP-7 expression was detected in the epidermis of involved and uninvolved psoriatic skin. In involved skin, MMP-7 was expressed by basal and mostly suprabasal keratinocytes. In uninvolved skin, expression of MMP-7 was restricted to basal keratinocytes. CONCLUSION: MMP-7 is independently associated to psoriasis disease and to inflammatory response which make it a potential biomarker for this dermatosis.

Altered Semen Quality is Associated with Decreased Semen Docosahexaenoic Acid and Increased Oleic Acid Levels.

BACKGROUND: Fatty acids composition of the spermatozoa may be an important determinant of sperm quality and fertility. This study aimed to evaluate the fatty acids profile of seminal plasma and membrane spermatozoa and to study the association between fatty acids and sperm properties. METHODS: Semen samples were collected by masturbation from 45 middle-aged men consulting for infertile couples. Semen cytomorphological analysis was performed after liquefaction. Semen was classified as normal or abnormal according to World Health Organization criteria 2010. Plasma seminal and spermatozoa membrane fatty acids composition were analyzed by capillary gas chromatography. RESULTS: Docosahexaenoic acid level was decreased while oleic acid level and n-6:n-3 ratio were increased in spermatozoa membrane in men with abnormal sperm. However, no variation in seminal plasma fatty acid composition was found between men with normal and abnormal sperms. Spermatozoa docosahexaenoic acid was positively correlated with sperm concentration and progressive motility and inversely related to atypical spermatozoa number, while oleic acid showed the inverse correlations. CONCLUSIONS: Altered fatty acids composition in the spermatozoa membrane, especially a decreased docosahexaenoic acid content, is associated with poor sperm quality. Although a causal association could not be established, intervention that recovers normal spermatozoa fatty acid composition could contribute to improved sperm quality.

Matrix metalloproteinase-3 predicts clinical cardiovascular outcomes in patients with coronary artery disease: a 5 years cohort study.

Matrix metalloproteinases (MMPs) are implicated in atherosclerosis evolution into a coronary artery disease (CAD). They could be used as biomarkers for a predictive approach when they are studied simultaneously. We aim in our study to demonstrate prospectively in patients with history of CAD that MMPs level is linked to clinical cardiovascular outcomes. Two hundred and eighteen patients diagnosed with CAD were followed prospectively for 5 years in the Cardiology Department of la Rabta Hospital University. Clinical cardiovascular outcomes during the period of the cohort were recorded. Measures were performed for biological and matrix markers at baseline. MMP-3, MMP-8, MMP-9, TIMP-1 and TIMP-2 were measured by ELISA in Sandwich assay. Fifty-nine cardiovascular outcomes occurred during the cohort period. By multivariate analysis, only MMP-3 persisted as a predictor for cardiovascular events even after adjustment. This metalloproteinase have been shown to be an independent predictor for cardiovascular outcomes (HR = 3.01; CI (1.3-6.95). The found cut-off value by receiver operating curve (ROC) was used for Kaplan-Meier analysis and revealed that patients with MMP-3 level higher than 9.3 ng/mL had a lower survival rate (p = 0.03). MMP-3 baseline level in patients with history of CAD is a potential predictor for cardiovascular outcomes.

Interaction Effects of Plasma Vitamins A, E, D, B9, and B12 and Tobacco Exposure in Urothelial Bladder Cancer: A Multifactor Dimensionality Reduction Analysis.

The study aimed to examine circulating vitamins A, E, D, and B12 and folate in patients with urothelial bladder cancer (UBC) and detect potential interaction effects of these micronutrients on UBC risk. A case-control study was conducted on 262 UBC patients and 254 matched controls. Vitamins A and E were assessed by ultra performance liquid chromatography, and vitamins D and B12 and folate were assessed by immunological methods. Binary logistic regression models were used to test associations of plasma vitamins tertiles with UBC risk. A multifactor dimensionality reduction method (MDR) was applied to assess interactive effects of the vitamins and tobacco on UBC risk. Higher levels in vitamins A, E, and D were associated with lower occurrence of UBC. No significant association was observed in plasma folate or vitamin B12 with UBC. There were redundancy interactions of plasma vitamin D with tobacco and with plasma vitamin A on UBC risk. Even though the study could not ascertain causality, the findings suggest that vitamins A, E, and D might be protective against UBC. Vitamins A and D interact antagonistically with each other's and with tobacco to modulate UBC risk. These interactions should be taken in consideration for the prevention of UBC.

Associations of rs1883832 and rs4810485 polymorphisms of CD40 gene with myocardial infarction in the Tunisian population.

Context: Cluster of differentiation 40 (CD40), and its ligand CD40L, are major co-stimulatory molecules whose interactions are important in both cellular and humoral immunity, and has been suggested to play a role in the pathogenesis of acute coronary syndrome. Objective: The aim of this study was to examine the association of CD40 polymorphisms (-1 C>T (rs1883832) and 945G>T (rs4810485)) and myocardial infarction (MI), and to test the association of CD40 gene haplotypes with MI in Tunisians. Materials and methods: Three hundred and fifty MI patients and 301 apparently healthy controls were included in the study. The polymorphisms of CD40 were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results: There were significant differences in the genotype and allele frequencies of CD40 gene -1 C>T (rs1883832) polymorphism between cases and controls. Stratifying according to gender, the association between the TT genotype and MI was statistically significant in males, only. Haplotype analysis revealed that the C-T and T-G haplotypes were associated with an increased risk of MI (p = 0.012 and p < 0.001, respectively). Conclusions: Our work showed a significant association between the -1 C>T (rs1883832) polymorphism of the CD40 gene and MI in the Tunisians.

Haplotype-based association of Vascular Endothelial Growth Factor gene polymorphisms with urothelial bladder cancer risk in Tunisian population.

BACKGROUND/AIM: Accumulated data suggested that Vascular Endothelial Growth Factor is a major mediator in vasculogenesis, angiogenesis and recently in tumorigenesis. Therefore, we aimed to investigate for the first time the association between VEGF gene variants (-2549I/D (rs35569394), -2578C/A (rs699947), and +936C/T (rs3025039)) with urothelial bladder cancer (UBC) in Tunisian population. METHODS: A total of 218 UBC patients and 204 controls were recruited and genotyped by Polymerase Chain Reaction technique. Odds ratios (OR) and 95% confidence intervals (CIs) were used to access the association between the VEGFA gene polymorphisms and UBC. RESULTS: We found a significant decreased risk association of -2578 C/A polymorphism with UBC (OR (95% CI), 0.62 (0.41-0.94), P = .026) for CA genotype and (OR (95% CI), 0.40 (0.21-0.76), P = .005) for double homozygous mutant genotype. No associations were found in case of both polymorphic sites of VEGF, vis. -2549I/D and +936C/T, respectively. Haplotype analysis revealed a strong linkage disequilibrium between -2578C/A and -2549I/D and CIC combination is the significant haplotype associated with increased risk of UBC (OR (95% CI), 3.63 (1.47-8.97), P = .005). Regarding tumor grade/stage and family history of cancer, no associations were found for -2578C/A polymorphism. CONCLUSION: CIC haplotype of VEGF gene may be important risk factor for UBC development in Tunisia.

X-linked Adrenoleukodystrophy, The Tunisian Experience.

BACKGROUND: X-linked adrenoleukodystrophy is a genetic disease affecting the degradation of very long chain fatty acids. This study aims to describe the clinical phenotype and biochemical feature of Tunisian patients; it also seeks to describe recognition of pattern analysis on the level of very long chain fatty acids in plasma for the visual discrimination of X-linked patients from a healthy group. METHODS: During the last 21 years, 19 patients were diagnosed with X-linked adrenoleukodystrophy based on the clinical features combined with the area percentage of hexacosanoic acid (C26:0) as well as the ratio of C26:0 and lignoceric acid (C24:0) relative to behenic acid (C22:0) by gas chromatography. For the biochemical diagnosis of X-ALD with better accuracy, it has been desired to transform the numerical values of these biochemical markers into visually discriminating patterns. RESULTS: The clinical features of 19 patients aged between 4 to 47 years were classified into cerebral form (57.8%), adrenomyeloneuropathic (26.3%), and a few patients were asymptomatic. The ratio C24:0/C22:0 ranged from 1.12 to 2.41 (normal value: 0.46 - 0.9) and C26:0/C22:0 ratio ranged from 0.03 to 0.36 (normal value: 0.003 - 0.009). The concentration of fatty acids with 22 or more carbons in body fluid did not change with age in control subjects and patients. For the visual diagnostic of patients, the Scatter plot was a reliable method for the diagnostic patterns of very long chain fatty acids of patients with X-linked adrenoleukodystrophy disorders. CONCLUSIONS: The incidence of X-linked adrenoleukodystrophy disorders is under diagnosed in Tunisia. The diagnosis was confirmed by enzymatic activity study and molecular analysis but the analysis of very long chain fatty acids by gas chromatography remains a reliable tool for the diagnosis and early initiation of the treatment.

Plasma total homocysteine: usual values and main determinants in adults living in the Great Tunis region.

BACKGROUND: Elevated total plasma homocysteine (tHcy) is an established risk factor for occlusive vascular disease and is thought to increase the risk of pregnancy loss, birth defects, and cognitive impairment in the elderly. OBJECTIVES: To determine tHcy standard values and the prevalence of hyperhomocysteinemia (HHC) and to examine their association with demographic and life style factors in the Greater Tunis population. METHODS: This cross-sectional study included 2712 subjects (1228 males and 1484 females) aged 35 - 70 years, living in the Greater Tunis region. tHcy was analyzed by a fluorescent polarizing immunoassay method. HHC was considered as tHcy > or = 15 micromol/L. RESULTS: HHC was observed in 23.7% of subjects. Plasma tHcy was higher in males than females (median (5th - 95th percentile): 13.5 [8.75 - 26.3] micromol/L vs. 10.7 [6.94 - 19.6] micromol/L). The tHcy concentration was significantly increased in smokers, alcoholics, in subjects with vitamin B12 and folate deficiencies, and hyperuricemia. In multivariate analysis, HHC was associated with male gender, vitamin B12 deficiency, clearance of creatinine, alcohol consumption, and hyperuricemia. CONCLUSIONS: HHC is common in Tunisian adults. Male gender, advanced age, renal insufficiency, low vitamin B12 status, hyperuricemia, and alcohol consumption are the main determinants of HHC in this population.

G protein beta3 subunit gene C825T and angiotensin converting enzyme gene insertion/deletion polymorphisms in hypertensive Tunisian population.

BACKGROUND: We investigated the interaction between the G protein beta3 subunit (GNB3) C825T variant and angiotensin converting enzyme (ACE) Insertion/Deletion (I/D) polymorphism in hypertensive Tunisian population. METHODS: Analyses of ACE and GNB3 genotypes were performed in 388 hypertensive patients and 425 healthy controls by polymerase chain reaction-restriction fragment length polymorphism. The plasma ACE activity was determined by a spectrophotometric method. RESULTS: The ACE genotype distribution and allele frequencies were not significantly different between the hypertensive and normotensive subjects (p > 0.05). This polymorphism was not associated with hypertension (HTA) (OR = 0.93, 95% CI = 0.75 - 1.15; p = 0.50). In cases, subjects carrying the DD genotype exhibited higher plasma ACE activity than those with ID and II genotypes (p = 0.001). In this group, a linear regression analysis revealed that the ACE I/D polymorphism is independently associated with plasma ACE activity (p = 0.017). The genotypic distribution and allelic frequencies of the GNB3 C825T polymorphism were not significantly different between the two groups. This polymorphism was found to have no effect on the risk of HTA (OR = 1.14, 95% CI = 0.93 - 1.39; p = 0.21). We did not observe a significant interaction between the GNB3 gene and the ACE gene with HTA. CONCLUSIONS: In this study, the I/D polymorphism is a significant independent predictor for variability of plasma ACE activity but the ACE I/D and GNB3 C825T polymorphisms are not significant factors for HTA in the Tunisian population. Moreover, we found no interaction between ACE D allele and GNB3 825T allele solely or combined with respect to HTA in the Tunisian population.

Lack of association between C3123A polymorphism of the angiotensin II type 2 receptor gene and hypertension in Tunisian population.

BACKGROUND: Hypertension is a polygenic disease. Various singlenucleotide gene polymorphisms of renin angiotensin system have been explored in hypertension. Angiotensin II, the major biologically active component of this system, exerts its effect via two pharmacologically distinct subtypes of angiotensin II receptors, the angiotensin II type 1 receptor and the angiotensin II type 2 receptor. AIM: To examine whether the 3123 C/A polymorphism of angiotensin II type 2 receptor gene is involved in hypertension in a sample of Tunisian population. METHODS: Atotal of 403 normotensive subjects and 382 hypertensive patients were included in the study. Genotyping was performed by polymerase chain reaction followed by Alu I restriction digestion. RESULTS: The frequency of "A" genotype was not significantly different between the two groups in men (¯2=1.18; p=0.16). The estimated odds prevalence for hypertension ("A" versus "C") was 0.77 (95% CI 0.49 to 1.22, p=0.27). After adjustment for confounding factors, the OR for hypertension remained no significant (OR: 1.49, 95% CI: 0.84-2.63, p=0.16). In women, genotype distributions for C3123A variant in hypertensive patients were not significantly different from normotensive subjects (¯2=3.16; p=0.20). Multiple logistic regression analysis showed that the AA genotype was not significantly associated with hypertension (OR: 1.09, 95% CI: 0.58-2.06, p=0.77). CONCLUSION: In the present study, we showed that the 3123 C/A polymorphism of AGT2R gene is not a significant factor for hypertension in a sample of Tunisian population.