Importance of the reticulocyte hemoglobin equivalent in the exclusion of latent iron deficiency.

BACKGROUND: Iron deficiency is an underdiagnosed public health problem, especially in developing countries, that can conceal serious underlying illnesses. Early diagnosis and treatment of latent iron deficiency (LID) is crucial. Reticulocyte hemoglobin equivalent (RET-He), was reported to be a cost-effective tool that reflects the iron availability at erythropoiesis. The aims of this study were to evaluate the RET-He in the exclusion of LID. METHODS: Transversal study was carried out in the laboratory of clinical biology of Ben Arous regional hospital, it included volunteers in apparently good health. We performed a complete blood count and a serum ferritin assay. Participants with normal hemoglobin were divided into two groups: Control group G1: normal ferritin (≥ 15 ng/mL)/LID group G2: low ferritin (< 15 ng/mL). We compared the blood count parameters of the two groups. RESULTS: We selected 108 participants (G1: 88 (81.5%), G2: 20 (18.5%)), mean age = 36 years, gender-ratio = 0.92. We noted, in G2, significantly lower rates for hemoglobin Hb (p < 0.001), hematocrit (p < 0.001), mean corpuscular hemoglobin MCH (p = 0.026), reticulocyte count (p = 0.039) and RET-He (p < 0.001) and significantly higher rate for RDW/CV (p = 0.009). RET-He averages were 29.1 pg in G2 and 31.1pg in G1. In multivariate analysis, only RET-He showed a significant difference between the two groups. Area under the curve was 0.872, the cutoff = 30.9 (sensitivity 100%, specificity 61%, PPV 37%, NPV 100%). CONCLUSION: RET-He is an accessible and affordable parameter of the iron status, with an excellent NPV. It would be interesting to evaluate our results on a larger sample to define reference values in our population.

MPC2 variants disrupt mitochondrial pyruvate metabolism and cause an early-onset mitochondriopathy.

Pyruvate is an essential metabolite produced by glycolysis in the cytosol and must be transported across the inner mitochondrial membrane into the mitochondrial matrix, where it is oxidized to fuel mitochondrial respiration. Pyruvate import is performed by the mitochondrial pyruvate carrier (MPC), a hetero-oligomeric complex composed by interdependent subunits MPC1 and MPC2. Pathogenic variants in the MPC1 gene disrupt mitochondrial pyruvate uptake and oxidation and cause autosomal-recessive early-onset neurological dysfunction in humans. The present work describes the first pathogenic variants in MPC2 associated with human disease in four patients from two unrelated families. In the first family, patients presented with antenatal developmental abnormalities and harboured a homozygous c.148T>C (p.Trp50Arg) variant. In the second family, patients that presented with infantile encephalopathy carried a missense c.2T>G (p.Met1?) variant disrupting the initiation codon. Patient-derived skin fibroblasts exhibit decreased pyruvate-driven oxygen consumption rates with normal activities of the pyruvate dehydrogenase complex and mitochondrial respiratory chain and no defects in mitochondrial content or morphology. Re-expression of wild-type MPC2 restored pyruvate-dependent respiration rates in patient-derived fibroblasts. The discovery of pathogenic variants in MPC2 therefore broadens the clinical and genetic landscape associated with inborn errors in pyruvate metabolism.

Neurofilaments: a key new biomarker for clinicians. Part 1: Importance of neurofilaments in the management of neurodegenerative diseases / Les neurofilaments : un nouveau biomarqueur clé pour les cliniciens. Partie 1 : Intérêt des neurofilaments dans la prise en charge des maladies neurodégénératives

Neurological biomarkers are of great use for clinicians, as they can be used for numerous purposes: guiding clinical diagnosis, estimating prognosis, assessing disease stage and monitoring progression or response to treatment. This field of neurology has evolved considerably in recent years due to analytical improvements in assay methods, now allowing the detection of biomarkers not only in cerebrospinal fluid (CSF) but also in blood. This progress greatly facilitates the repeated quantification of biomarkers, the collection of blood being much less invasive than that of CSF. Among the various informative biomarkers of neurological disorders, neurofilaments light chains (NfL) have proven to be particularly attractive in many contexts, in particular for the diagnosis and prognosis of neurodegenerative diseases (which this review will present), but also in other contexts of neurological disorders (which will be detailed in part 2). We further address the added value of NfL compared to other biomarkers commonly used to monitor the diseases described in this review.

Les biomarqueurs neurologiques sont d'une grande utilité, car ils peuvent être utilisés à de nombreuses fins : orienter le diagnostic clinique, estimer le pronostic, évaluer le stade de la maladie et surveiller la progression ou la réponse au traitement. Ce domaine de la neurologie a considérablement évolué ces dernières années grâce à l'amélioration des méthodes de dosage, permettant désormais la détection de biomarqueurs non seulement dans le liquide cérébro-spinal (LCS) mais aussi dans le sang. Ce progrès facilite la quantification répétée des biomarqueurs, le prélèvement de sang étant beaucoup moins invasif que celui du LCS. Parmi les différents biomarqueurs informatifs des troubles neurologiques, la chaîne légère des neurofilaments (NfL) s'est révélée particulièrement intéressante dans de nombreux contextes, notamment pour le diagnostic et le pronostic des maladies neurodégénératives (que cette revue présentera), mais aussi dans d'autres contextes de troubles neurologiques (qui seront détaillés dans la partie 2). La valeur ajoutée du NfL par rapport aux autres biomarqueurs couramment utilisés est analysée.

Neurofilaments: a key new biomarker for clinicians. Part 2: Neurofilaments, an asset beyond neurodegenerative diseases / Les neurofilaments : un nouveau biomarqueur clé pour les cliniciens. Partie 2 : Neurofilaments, un intérêt au-delà des maladies neurodégénératives.

Neurofilaments (Nf) are proteins selectively expressed in the cytoskeleton of neurons, and their increase is a marker of neuronal damage. The potential utility of neurofilament light chain (NfL) has recently increased considerably, well beyond neurodegenerative diseases, due to analytical advances that allow measurement of their concentrations (even low ones) in cerebrospinal fluid and blood. This article completes the first part, in which we presented the interest of NfL in the context of neurodegenerative diseases. Here we focus our review on other clinical contexts of neurological injury (such as traumatic brain injury, multiple sclerosis, stroke, and cancer) and present the potential value of NfL assay in the management of these patients, for both diagnosis and prognosis. We also discuss the added value of the NfL assay compared to other biomarkers commonly used in the described clinical situations.

Les neurofilaments (Nf) sont des protéines sélectivement exprimées dans le cytosquelette des neurones, dont l'augmentation est un marqueur de dommages neuronaux. L'utilité potentielle de la chaîne légère des neurofilaments (NfL) s'est récemment considérablement accrue, bien au-delà des maladies neurodégénératives, grâce aux progrès analytiques permettant de mesurer leurs niveaux (mêmes faibles) dans le liquide cérébro-spinal et le sang. Cet article complète la première partie, dans laquelle nous avions présenté l'intérêt des NfL dans le contexte des maladies neurodégénératives. Nous axons ici notre revue sur d'autres contextes cliniques de lésions neurologiques (tels que les traumatismes crâniens, la sclérose en plaques, les accidents vasculaires cérébraux et le cancer) et présentons l'intérêt potentiel du dosage des NfL pour la prise en charge de ces patients, tant au niveau diagnostique que pronostique. Nous discutons également de la plus-value du dosage des NfL par rapport aux autres biomarqueurs couramment utilisés dans les contextes cliniques décrits.

Neurofilaments contribution in clinic: state of the art.

Neurological biomarkers are particularly valuable to clinicians as they can be used for diagnosis, prognosis, or response to treatment. This field of neurology has evolved considerably in recent years with the improvement of analytical methods, allowing the detection of biomarkers not only in cerebrospinal fluid (CSF) but also in less invasive fluids like blood. These advances greatly facilitate the repeated quantification of biomarkers, including at asymptomatic stages of the disease. Among the various informative biomarkers of neurological disorders, neurofilaments (NfL) have proven to be of particular interest in many contexts, such as neurodegenerative diseases, traumatic brain injury, multiple sclerosis, stroke, and cancer. Here we discuss these different pathologies and the potential value of NfL assay in the management of these patients, both for diagnosis and prognosis. We also describe the added value of NfL compared to other biomarkers currently used to monitor the diseases described in this review.

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.

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.

[Hypercalcemia related to PTH-rP revealing malignant hepatic epithelioid hemangioendothelioma]. / Une hypercalcémie humorale maligne révélant un hémangioendothéliome épithélioïde du foie.

Hypercalcemia caused by tumor production of PTH-rp occurs most often in cases of squamous cell carcinoma of the lung, aerodigestive tract cancer, gynecological cancer and lymphoma. We report an exceptional case of PTH-rp related to a hepatic hemangioendothelioma. A 70 years-old male admitted for deterioration of the general state. The laboratory investigations revealed hypercalcemia, related to tumor production of PTH-rp. Imaging revealed tumoral hepatic lesions. Histopathological study and immunohistochemistry showed diffuse response for CD31 marker, CK20 (+) with CK7 (-) and hepatocyt antigen (-). The diagnosis of PTH-rp related to hepatic hemangioendothelioma was make. The patient died with recurrence of fatal hypercalcemia. Management of patients presenting with humoral hypercalcemia includes a vigorous search for tumor lesions. Elevated PTH-rp can be a bad prognostic factor. In front of tumoral liver lesions, a hepatic epithelioid hemangioendothelioma must be considered. Immunohistochemistry is necessary to make diagnosis.

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.

Clinical and Biochemical Profile of Tyrosinemia Type 1 in Tunisia.

BACKGROUND: Hereditary tyrosinemia type 1 (HT1) is an autosomal recessive disease caused by a defect of fumarylacetoacetate hydrolase. This study aimed to estimate the prevalence of HT1 in Tunisia and report its clinical, biochemical and genetic features. METHODS: During the last 25 years, 69 patients were diagnosed with HT1 based on clinical features and increased succinylacetone (SA) in blood and urine. SA was detected by GC-MS after oximation and quantified by a spectrophotometric method. Nine prenatal diagnoses for HT1 have been done and nine unrelated patients were screened for the hotspot IVS6-1(G-T) mutation using PCR. RESULTS: Using the Hardy-Weinberg formula, the incidence of HT1 was estimated at 1/14804 births in Tunisia. According to clinical form, 21 patients (30%) had the acute form and 48 patients (70%) had the chronic form. Mean plasma and urine SA were higher in the acute form (24 and 193 µmol/L vs. 9 and 90 µmol/L, respectively). Diagnosis of HT1 was done for 4 fetuses. The hotspot IVS6-1(G-T) mutation was found in six of nine explored patients. CONCLUSIONS: The incidence of HT1 is relatively high in Tunisia with a predominance of the chronic form. It is important to diagnose the disease as early as possible to prevent unfavorable issues. Prenatal diagnosis should be recommended to minimize the recurrence of the disease.

Fortuitous description of haemoglobin A2' [δ16 (A13) Gly→Arg (GGC→CGC)] in a Tunisian family: study of the molecular defect and its origin.

The most common inherited haemoglobin disorders encountered in Tunisia are ß-thalassemia and sickle cell disease, which result from mutations in the ß-globin gene. Few studies focused on δ-globin gene variations responsible for δ-thalassemia or HbA2 variants. HbA2' [δ16 (A13) Gly→Arg (GGC→CGC)] is a δ-chain variant that has been identified in several populations of African origin. We report herein for the first time the description of HbA2' in the Tunisian population. Identification of HbA2' in the studied family was carried out by high-performance liquid chromatography and confirmed by sequencing analyses of the whole δ-globin gene. Haplotypes of the ß-globin gene cluster were constructed by mapping the restriction sites using polymerase chain reaction followed by enzymatic digestion. Compound heterozygosity of HbA2' with HbO-Arab was identified in the proband. The mother and two other siblings showed heterozygous HbA2' whereas the father showed heterozygous HbO-Arab. The sum of HbA2 and HbA2' in all cases was less than 4%, thus excluding ß-thalassemia. ß-cluster haplotype analysis revealed that this mutation was associated with the F haplotype (-+--+++). The unique origin of this mutation in Africa is likely since the linked ß-cluster haplotype is one of the major haplotypes found in African populations.

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.

Dyslipidemia in the Greater Tunis population: prevalence and determinants.

BACKGROUND: Economic development and socio-demographic changes have led to increased frequency of cardiovascular disease and other chronic diseases in Tunisia. OBJECTIVES: To assess the prevalence of different types of dyslipidemia and to examine their association with sociodemographic characteristics in the Greater Tunis population. METHODS: The study included 2712 subjects (1228 men and 1484 women) aged 35-70 years, recruited during the years 2004 and 2005 from the Greater Tunis population. Hypercholesterolemia, hypertriglyceridemia, and low HDL cholesterol were defined according to the National Cholesterol Education Program-Adult Treatment Panel III. RESULTS: The prevalence of hypercholesterolemia, hypertriglyceridemia, and low HDL cholesterol was 40.8% (34.9% in males and 45.8% in females; p < 0.001), 29.2% (31.1% in males and 27.6% in females; p < 0.05), and 21.2% (32.5% in males and 11.5% in females; p < 0.001), respectively. The prevalence was higher in urban than rural regions. Hypercholesterolemia was more frequent in illiterate women and in men with high education level. CONCLUSIONS: Dyslipidemias are common in Tunisians, mainly in urban areas, in illiterate women as well as in men with high levels of education. Profound changes of life style and dietary habits of Tunisians are needed to reduce the risk of cardiovascular diseases.

C(-260)T polymorphism in the promoter of CD 14 gene is not associated with myocardial infarction in the Tunisian population.

Recent findings suggest that inflammation plays a role in atherosclerosis and its acute complications. Several known mechanisms may play at least a partial role in this process. One of the most likely mechanisms involves lipopolysaccharide (LPS) and its receptor, CD14. The C(-260)T single nucleotide polymorphism (rs2569190) in the promoter region of the CD14 receptor gene has been reported to be associated with a higher risk of MI. Others studies, however, have not corroborated these findings. Considering the contradictory results, the aim of the present study was to investigate the possible association between the CD14 C(-260)T polymorphism and the risk of MI in the Tunisian population. A total of 321 Tunisian patients with MI and 344 healthy controls were included in the study. Genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. The frequency of TT homozygous genotype for the CD14 C(-260)T polymorphism was 26.2% in MI patients and 27.0% in the control group. However, the genotype distribution and allele frequencies were not significantly different between MI and controls subjects. Moreover, the odds ratio for MI associated with the TT genotype failed to reach statistical significance (OR=1.22; 95% CI: 0.85-1.77; p=0.272). These results do not support the hypothesis that the C-260T polymorphism of CD14 gene contributes to the genetic susceptibility to MI in the Tunisian population studied.

Association between -786TC polymorphism in the endothelial nitric oxide synthase gene and hypertension in the Tunisian population.

BACKGROUND: Nitric oxide (NO) is produced by endothelial cells and serves as a potent vasodilator. Several lines of evidence have shown that NO plays an important role in the regulation of blood pressure and regional blood flow. Recent genetic studies have shown an association between the -786TC polymorphism in the endothelial nitric oxide synthase gene (NOS3) and coronary artery diseases, but any possible association with hypertension has been controversial. In the present study, we examined a possible association between the -786TC polymorphism of the NOS3 gene and hypertension in a sample of the Tunisian population. METHODS: A total of 288 unrelated Tunisian patients with hypertension and 373 normotensive subjects were included in the study. The -786TC gene polymorphism was analyzed by PCR-RFLP. RESULTS: A significant difference in genotype distribution and allele frequency was observed between patients and controls. Patients with hypertension had a frequency of 19.7% for CC genotype, 52.9% for TC genotype and 27.3% for TT genotype. The control had a frequency of 14.7% for the CC genotype, 47.2% for the TC genotype and 38.1% for the TT genotype (χ²=9.09, p=0.01). The hypertension patient group showed a significant higher frequency of the C allele compared to the controls (0.46 vs. 0.38; χ²=8.26, p=0.004). The odds ratio of hypertension for C vs. T allele frequencies was statistically significant 1.59 (1.14-2.21) at 95% CI, p = 0.004 in men, whereas it was non-significant in women 1.21 (0.87-1.67), p=0.23. CONCLUSION: The present study showed a significant and independent association between the -786TC gene polymorphism (presence of C allele) and hypertension in the Tunisian population.

[Erythrocyte abnormalities in thyroid dysfunction]. / Les anomalies ertyrocytaires au cours des dysthyroïdies.

BACKGROUND: Erythrocyte abnormalities are frequently associated with thyroid dysfunction. However, they are rarely investigated and related to the thyroid. AIM: This study was aimed to determine the nature and frequency of erythrocyte abnormalities in thyroid disease and look for their evolution after thyroid function restoration. METHODS: This retrospective study included 412 patients with peripheral thyroid disease; hyperthyroidism (n=235) or hypothyroidism (n=177). Hyperthyroidism was considered for TSH<0.10 ÌUI/ml and hypothyroidism for TSH>5.0 ÌUI/ml. Anemia was defined by hemoglobin level<13 g/dl in men and <12 g/dl in women, microcytosis by mean corpuscular volume (MCV)<80 fl, macrocytosis by MCV>98 fl, and hypochromia by mean corpuscular hemoglobin (MCH)<25 pg. Restoration of euthyroid state was considered in patients with normal TSH levels for at least 3 months. RESULTS: Anaemia was observed in 40.9% of patients with hyperthyroidism and 57.1% of patients with hypothyroidism. Among these, normocytic or macrocytic anaemia was present in 46.3% of cases. Whereas, microcytosis, with or without anaemia, was noted in 87.7% of patients with hyperthyroidism. FT4 was positively correlated with the number of red blood cells and haemoglobin, and inversely correlated with MCV and MCH. After restoration of euthyroid state, most erythrocyte abnormalities were corrected. CONCLUSION: Thyroid diseases are frequently associated with erythrocyte abnormalities, including normocytic anaemia in hypothyroidism and microcytosis in hyperthyroidism. These abnormalities should be investigated and corrected. Their presence could steer towards subclinical thyroid dysfunction, allowing its early management.

[Minor beta thalassemia masked by a hemoglobin A2 mutant]. / Une bêta thalassémie mineure masquée par un mutant de l'hémoglobine A2.

BACKGROUND: The elevation of hemoglobin A2 (HbA2) is an essential criterion in the diagnosis of minor ss thalassemia. AIM: To report a case of minor ss thalassemia HbA2 with normal HbA2 rate. OBSERVATION: We report the case of ten years old boy, with hypochromic microcytic anemia, refractory to iron treatment. The study of hemoglobin (Hb) has revealed the presence of a minor abnormal fraction of Hb, amounted to 2.8%, associated with the presence of HbF and normal levels of HbA2. Family study revealed the presence of two Hb abnormalities (ss thalassemia trait and HbA2 mutant) transmitted to offspring in isolation or associated. The genotypic study confirmed the presence of minor, 0 thalassemia and a °/00 gene mutation, causing a new mutant HbA2 named HbA2 Pasteur-Tunis [°/00 59(E3)LysgAsn(AAGgAAC)]. CONCLUSION: The presence of °/00 mutant reduces HbA2 level and could hide ss thalassemia trait. Rigorous and methodical interpretation of phenotypic data is crucial to not overlook the presence of ss thalassemia trait, whose diagnosis is crucial for genetic counseling and prenatal diagnosis.