Molecular and computational characterization of ABCB11 and ABCG5 variants in Tunisian patients with neonatal/infantile low-GGT intrahepatic cholestasis: Genetic diagnosis and genotype-phenotype correlation assessment

Many inherited conditions cause hepatocellular cholestasis in infancy, including progressive familial intrahepatic cholestasis (PFIC), a heterogeneous group of diseases with highly overlapping symptoms. In our study, six unrelated Tunisian infants with PFIC suspicion were the subject of a panel-target sequencing followed by an exhaustive bioinformatic and modeling investigations. Results revealed five disease-causative variants including known ones: (the p.Asp482Gly and p.Tyr354 * in the ABCB11 gene and the p.Arg446 * in the ABCC2 gene), a novel p.Ala98Cys variant in the ATP-binding cassette subfamily G member 5 (ABCG5) gene and a first homozygous description of the p.Gln312His in the ABCB11 gene. The p.Gln312His disrupts the interaction pattern of the bile salt export pump as well as the flexibility of the second intracellular loop domain harboring this residue. As for the p.Ala98Cys, it modulates both the interactions within the first nucleotide-binding domain of the bile transporter and its accessibility. Two additional potentially modifier variants in cholestasis-associated genes were retained based on their pathogenicity (p.Gly758Val in the ABCC2 gene) and functionality (p.Asp19His in the ABCG8 gene). Molecular findings allowed a PFIC2 diagnosis in five patients and an unexpected diagnosis of sisterolemia in one case. The absence of genotype/phenotype correlation suggests the implication of environmental and epigenetic factors as well as modifier variants involved directly or indirectly in the bile composition, which could explain the cholestasis phenotypic variability.

[Rheumatic cardiopathies and its risk factors: about 50 cases]

INTRODUCTION

Acute rheumatic fever (ARF) is a multi-systemic disease, in which cardiac involvement is the most serious major manifestation of disease. The aim of this study was to analyse cardiac involvement in children with ARF and his risk factors.

MATERIALS AND METHODS

It were a retrospective study including all children under the age of 14 years who were hospitalized for ARF in the pediatric department of the CHU Hédi Chaker of Sfax, during a period of twelve years (2010-2022).

RESULTS

We collected 50 cases (31 boys and 19 girls). Twenty-two patients (44%) developed cardiac lesions. The mean age at diagnosis was 9.6 years [5-14 years]. A pathological heart murmur was detected in 14 cases (n = 14/22) was classified as mild carditis in 15 cases, moderate carditis in 5 cases and severe in 2 cases. The median follow-up time was 3,3 years. Nineteen patients developed valvular sequelae Risk factors of cardiac lesions was: age more than 8 years, heart murmur, allonged PR, CRP > 100 mg/l and VS > 100 mm.

CONCLUSION

CR is still a public health problem in Tunisia. It is a serious pathology that can cause serious increases in morbidity rates. Thus, we must strengthen preventive strategies.

Preparation and Characterization of New and Low-Cost Ceramic Flat Membranes Based on Zeolite-Clay for the Removal of Indigo Blue Dye Molecules

Composite flat membranes were prepared using a dry uniaxial pressing process. The effect of the sintering temperature (850-950 °C) and smectite proportion (10-50 wt.%) on membrane properties, such as microstructure, mechanical strength, water permeability, and treatment performances, was explored. It was observed that increasing the sintering temperature and adding higher amounts of smectite increased the mechanical strength and shrinkage. Therefore, 850 °C was chosen as the optimum sintering temperature because the composite membranes had a very low shrinkage that did not exceed 5% with high mechanical strength, above 23 MPa. The study of smectite addition (10-50 wt.%) showed that the pore size and water permeability were significantly reduced from 0.98 to 0.75 µm and from 623 to 371 L·h-1·m-2·bar-1, respectively. Furthermore, the application of the used membranes in the treatment of indigo blue (IB) solutions exhibited an almost total turbidity removal. While the removal of color and COD decreased from 95% to 76%, respectively, they decreased from 95% to 52% when the amount of smectite increased. To verify the treated water's low toxicity, a germination test was performed. It has been shown that the total germination of linseed grains irrigated by MS10-Z90 membrane permeate was identical to that irrigated with distilled water. Finally, based on its promising properties, its excellent separation efficiency, and its low energy consumption, the MS10-Z90 (10 wt.% smectite and 90 wt.% zeolite) sintered at 850 °C could be recommended for the treatment of colored industrial wastewater.

Clinical and therapeutic characteristics of childhood uveitis in a tertiary center in Tunisia

INTRODUCTION

Childhood uveitis is a rare condition with various associated diagnostic and therapeutic challenges.

AIM

We proposed to describe the distribution, clinical findings, treatment, complications, and visual outcomes of uveitis in children at a tertiary referral center in Sfax, Tunisia.

METHODS

A retrospective study of 33 children (54 eyes) with uveitis collected over the period from January 2009 to December 2018 was carried out at the Ophthalmology Department of Habib Bourguiba University Hospital, Sfax, Tunisia. The data from the clinical examination, the etiological assessment, and the used treatments were collected. Standard diagnostic criteria were used for all uveitic syndromes or entities.

RESULTS

The mean age of the patients was 11.42 years with a male-to-female ratio of 0.74. Uveitis was bilateral in 63% of the patients. The most common anatomical form was intermediate uveitis (39%). Idiopathic cases accounted for 52%. The major complications were posterior synechiae, optic disc edema, cataract, and cystoid macular edema. Anti-infective treatment was prescribed in 24% of the patients. Oral corticosteroid therapy was used in 67% of the patients. 18% of the patients received immunosuppressive therapy and 6% received a biological agent. The mean final visual acuity was 4.6/10.

CONCLUSION

Childhood uveitis is a serious pathology with frequent and vision-threatening complications. The etiologies are variable and the assessment can remain negative. A rigorous diagnostic approach, an oriented etiological assessment in collaboration with the pediatrician, and an appropriate therapy are necessary for management.

Development of Ultrafiltration Kaolin Membranes over Sand and Zeolite Supports for the Treatment of Electroplating Wastewater

A high cost of high-purity materials is one of the major factors that limit the application of ceramic membranes. Consequently, the focus was shifted to using natural and abundant low-cost materials such as zeolite, clay, sand, etc. as alternatives to well-known pure metallic oxides, such as alumina, silica, zirconia and titania, which are usually used for ceramic membrane fabrication. As a contribution to this area, the development and characterization of new low-cost ultrafiltration (UF) membranes made from natural Tunisian kaolin are presented in this work. The asymmetric ceramic membranes were developed via layer-by-layer and slip-casting methods by direct coating on tubular supports previously prepared from sand and zeolite via the extrusion process. Referring to the results, it was found that the UF kaolin top layer is homogenous and exhibits good adhesion to different supports. In addition, the kaolin/sand and kaolin/zeolite membranes present an average pore diameter in the range of 4-17 nm and 28 nm, and water permeability of 491 L/h·m²·bar and 182 L/h·m²·bar, respectively. Both membranes were evaluated in their treatment of electroplating wastewater. This was done by removing oil and heavy metals using a homemade crossflow UF pilot plant operated at a temperature of 60 °C to reduce the viscosity of the effluent, and the transmembrane pressure (TMP) of 1 and 3 bar for kaolin/sand and kaolin/zeolite, respectively. Under these conditions, our membranes exhibit high permeability in the range of 306-336 L/h·m²·bar, an almost total oil and lead retention, a retention up to 96% for chemical oxygen demand (COD), 96% for copper and 94% for zinc. The overall data suggest that the developed kaolin membranes have the potential for remediation of oily industrial effluents contaminated by oil and heavy metals.

Treatment of Tuna Cooking Juice via Ceramic Ultrafiltration Membrane: Optimization Using Response Surface Methodology

In the present work, optimized ultrafiltration conditions, using a ceramic multi tubular titania membrane (150 KDa), were investigated for the treatment of tuna cooking juice, for water reuse in the industrial process. The interactive effects of the volume concentrating factor (VCF) (1.03-4.25), feed temperature (T) (20-60 °C), and applied transmembrane pressure (ΔP) (2-5 bar) on protein removal (R protein) and permeate flux (J) were determined. A Box-Behnken experimental design (BBD) with the response surface methodology (RSM) was used for statistical analysis, modeling, and optimization of the operating conditions. The analysis of variance (ANOVA) results proved that the protein removal and permeate flux were significant and represented good correlation coefficients of 0.9859 and 0.9294, respectively. Mathematical modeling showed that the best conditions were VCF = 1.5 and a feed temperature of 60 °C, under a transmembrane pressure of 5 bar. The fouling mechanism was checked by applying a polarization concentration model. Determination of the gel concentration confirmed the results found in the mass balance calculation and proved that the VCF must not exceed 1.5. The membrane regeneration efficiency was proven by determining the water permeability after the chemical cleaning process.

Custom Next-Generation Sequencing Identifies Novel Mutations Expanding the Molecular and clinical spectrum of isolated Hearing Impairment or along with defects of the retina, the thyroid, and the kidneys

Background

In the Tunisian population, the molecular analysis of hearing impairment remains based on conventional approaches, which makes the task laborious and enormously expensive. Exploration of the etiology of Hearing Impairment and the early diagnosis of causal mutations by next‐generation sequencing help significantly alleviate social and economic problems.

Methods

We elaborated a custom SureSelect^QXT panel for next‐generation sequencing of the coding sequences of 42 genes involved in isolated hearing impairment or along with defects of the retina, the thyroid, and the kidneys.

Results

We report eight pathogenic variants, four of which are novel in patients with isolated hearing impairment, hearing impairment, and renal tubular acidosis, Usher syndrome and Pendred syndrome. Functional studies using molecular modeling showed the severe impact of the novel missense mutations on the concerned proteins. Basically, we identified mutations in nuclear as well as mitochondrial genes in a Tunisian family with isolated hearing impairment, which explains definitely the phenotype detected since 2006.

Conclusion

Our results expanded the mutation spectrum and genotype‒phenotype correlation of isolated and syndromic hearing loss and also emphasized the importance of combining both targeted next‐generation sequencing and detailed clinical evaluation to elaborate a more accurate diagnosis for hearing impairment and related phenotypes especially in North African populations.

8q21.11 microdeletion syndrome: Delineation of HEY1 as a candidate gene in neurodevelopmental and cardiac defects

BACKGROUND

8q21.11 microdeletion syndrome is a rare chromosomal disorder characterized by recurrent dysmorphic features, a variable degree of intellectual disability and ocular, cardiac and hand/feet abnormalities. To date, ZFHX4 is the only candidate gene implicated in the ocular findings. In this study, we evaluated a patient with a de novo 8q21.13-21.3 deletion to define a new small region of overlap (SRO) for this entity.

METHODS

We conducted a clinical evaluation and comparative genomic hybridization (CGH) 4x44K microarrays in a patient with de novo unbalanced translocation t(8;16)(q21; q11.2).

RESULTS

The case, a 6-year-old boy, presented dysmorphic features including an elongated face, brachycephaly with a high forehead, an underdeveloped ala, thin upper lip, micrognathia, low-set ears, hypotonia, mild intellectual disability, cortical atrophy with thin corpus callosum defect, and an atrial septal defect. No ocular abnormalities were found. Microarray analysis revealed a 9.6 Mb interstitial 8q21.11-21.3 deletion, not including the ZFHX4 gene. This microdeletion was confirmed in our patient through qPCR analysis, and both parents had a normal profile. Alignment analysis of our case defined a new SRO encompassing five genes. Among them, the HEY1 gene is involved in the embryonic development of the heart, central nervous system, and vascular system. Hrt1/Hey1 null mice show perinatal lethality due to congenital malformations of the aortic arch and its branch arteries. HEY1 has also been linked to the maintenance of neural stem cells, inhibition of oligodendrocyte differentiation, and myelin gene expression.

CONCLUSION

HEY1 is a candidate gene for both neurological and cardiac features of the 8q21.11 microdeletion syndrome and might, therefore, explain specific components of its pathophysiology.

Removal of fluoride ions (F-) from aqueous solutions using modified Turkish zeolite with quaternary ammonium

The natural Turkish zeolite has been modified with hexadecyltrimethylammonium bromide (CTAB) for the elimination of fluoride (F^-) from aqueous solutions. The parent natural zeolite (NZ) and modified zeolite (MZ) have been characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), zeta potentials and Brunauer-Emmett-Teller (BET) method. The effect of pH, adsorbent dose, contact time, initial concentration and temperature on adsorption of fluoride ions onto modified zeolite (MZ) has been determined in batch experiments. Fluoride concentration can be reduced to 1.5 mg/L under the optimum condition (pH = 5, adsorbent dose = 20 mg/L, contact time = 60 min and T = 293 K) when initial fluoride concentration of 10 mg/L is employed. The fluoride adsorption on MZ has been described by the Langmuir isotherm and the maximum fluoride adsorption capacity was found as 2.994 mg/g. Kinetics data were best described by the pseudo-second-order model. The thermodynamic studies proved that the adsorption was exothermic and spontaneous.

[Epidemiology of home accidents in childhood: experience in the Division of General Pediatrics in Southern Tunisia]

Les accidents domestiques représentent un problème sérieux de santé publique en pédiatrie. Ils sont responsables d’une lourde morbidité et mortalité parmi la population pédiatrique. Nous avons mené une étude rétrospective colligeant 231 cas d’accidents domestiques chez l’enfant au Service de Pédiatrie de l’Hôpital Hédi Chaker de Sfax durant une période de 5 ans (2008 - 2012). Durant la période d’étude, nous avons colligé 231 cas d’accidents domestiques. Il s’agissait de 124 garçons (53,7%) et 107 filles (46,3%). L’âge moyen était de 2 ans avec des extrêmes de 1 jour et 14 ans. Les enfants âgés de moins de 4 ans étaient les plus exposés (88,7%). Les intoxications accidentelles étaient les accidents les plus fréquents (105 cas). Les caustiques étaient les agents toxiques les plus fréquents (33 cas), suivis par les médicaments (28 cas) puis les hydrocarbures (16 cas). Les accidents par corps étrangers ont représenté le deuxième mécanisme accidentel (64 cas). Il s’agissait de 43 cas d’inhalation de corps étrangers et 21 cas d’ingestion de corps étranger. Nous avons enregistré 28 cas de traumatismes; il s’agissait d’une chute d’une certaine hauteur dans 25 cas. Nous avons recensé 26 cas d’envenimations scorpioniques, 5 noyades, 2 cas de brulure et un seul cas d’électrisation. Les intoxications accidentelles et les accidents par corps étrangers représentent les principaux accidents domestiques dans notre série et la tranche d’âge entre 1 et 4 ans est la plus exposée aux accidents domestiques.

Hypoparathyroidism in children: a study of eight cases

BACKGROUND

Hypoparathyroidism is a rare pediatric endocrine disease, which is caused by low circulating levels of PTH or insensitivity to its action in the target tissues.

AIM

To report the clinical and biochemical characteristics and theoutcome of 8 patients with hypoparathyroidism.

METHODS

We analyzed retrospectively the results of clinical, biochemical, radiological findings of patients with hypoparathyroidism diagnosed in pediatric department of Hedi Chaker Hospital during the period 1994-2013.

RESULTS

Eight patients (5 females and 3 males) were diagnosed with hypoparathyroidism during 20 years's period. The median age at the onset of first symptoms was 17,5 months (15 days- 5 years and 10 months). Seizures were the most commonly presenting symptom and were seen in seven cases. Eight patients were diagnosed with hypoparathyroidism (Di-Georges syndrome: one case, Sanjad Sakati syndrome: 3 case, kearns sayre syndrome: 1 case, autoimmune polyendocrinopathy candidiasis- ectodermal dystrophy: one case, idiopathic hypoparathyroidism: two cases. Conventional treatment was based on calcium and vitamin D analogs. The average of follow up was 5 years. Nephrocalcinosis was noted in two patients. The death occurred in five patients; it was related to hypocalcaemia in one patient.

CONCLUSION

The diagnosis of hyperparathyroidism is easy; it's established on the association of hypocalcaemia and hyperphosphatemia. Etiologic approach is based on molecular findings. Vitamin D analog treatment of hypoparathyroidism in children involves the challenge, of adjusting treatment dosage to minimize both symptomatic hypocalcemia and asymptomatic, but potentially kidney-damaging, hypercalciuria causing nephrocalcinosis and renal insufficiency.

Adverse Reactions Due to the Bacillus Calmette-Guerin Vaccine: Twenty Tunisian Cases

Background

Bacillus Calmette-Guérin (BCG) vaccine is a widely used vaccine. Management of local BCG complications differs between clinicians, and the optimal approach remains unclear.

Aims

We aim to describe the epidemiological, clinical and therapeutic aspects of the BCG vaccine side effects in Sfax.

Patients and Methods

This was a retrospective study of all the cases of BCG vaccine adverse reactions recorded in the Dermatology and Paediatrics Departments of Hedi Chaker University Hospital of Sfax over a period of 10 years (2005-2015).

Results

Twenty cases of BCG adverse reactions were notified during the study period. Actually, 80% of the patients presented local adverse reactions. The outcome was good in all the followed patients. The rate of disseminated BCG disease was 20%. Biological tests of immunity showed a primary immunodeficiency in three cases, whereas the outcome was fatal in two cases.

Conclusion

BCG vaccine adverse reactions range from mild to severe. However, the management of benign local reactions remains unclear. Disseminated BCG disease must alert clinicians to the possibility of a primary immunodeficiency.

[Management of patients with major beta thalassemia in a paediatric department in the south of Tunisia: About 26 cases]

AIM

Our objectives were to assess the management of patients with major thalassemia and identify the various complications and monitoring means.

PATIENTS AND METHODS

A retrospective study was conducted on 26 β-thalassemic patients in the department of paediatrics, Hédi Chaker hospital, Sfax, Tunisia during a period of 25 years (from 1 January 1990 to 31 December 2014).

RESULTS

The mean age of the beginning of transfusion was 11.5 months. That was with phenotyped red blood cells but not leukodepleted blood. Twenty-three patients received chelation. Before 2001, all patients received deferoxamine, poor adherence to this treatment was observed in 66% of cases. It was replaced by deferiprone since 2006 and deferasirox since 2009. A combination of 2 or 3 chelators was indicated for four patients. A total splenectomy was performed in 10 cases patients; it was due to hypersplenism. The bone marrow transplant was performed for one patient at the age of 9 year but it was rejected. Many complications were detected: endocrine complications (19 cases), immune complications (9 cases), gallbladder stones (5 cases), cardiac complications (4 cases), osteoporosis (3 cases), infectious complications (3 cases) and thromboembolic complications (2 cases). We noted some side effects related to chelation therapy in twelve cases. Four patients were dead.

CONCLUSION

Improving the medical care of homozygous β-thalassemic children requires adherence to transfusion regimen and chelation therapy. Bone marrow transplantation remains the only possible curative therapy, which must be promoted in our country.

Management of cholestatic pruritus in children with Alagille syndrome: Case report and literature review

Alagille syndrome causes intractable pruritus and disfiguring xanthomas because of retained bile acids and cholesterol. Drug therapy in addition to surgical intervention may be effective in many patients in reducing serum bile acids, cholesterol levels, pruritus, and skin xanthomas. In this report, we describe a child with Alagille syndrome who presented with severe pruritus and xanthomas as a consequence of severe hypercholesterolemia and discuss the treatment modalities.

Clinical and Genetic Characterization of Tunisian Children with Hereditary 1,25-Dihydroxyvitamin D-Resistant Rickets

BACKGROUND

Hereditary vitamin D-resistant rickets (HVDRR) is an autosomal recessive disorder characterized by the early onset of rickets and is caused by mutations in the vitamin D receptor (VDR) gene. Some HVDRR patients also have alopecia.

PATIENTS AND METHODS

We retrospectively studied the clinical features, laboratory findings, genetic defects, as well as responses to treatment in a series of children with HVDRR.

RESULTS

Eight patients from 7 families met the inclusion criteria. Alopecia was noted in 7 patients. Two different homozygous mutations in the VDR gene were identified in 6 patients: the p.K45E mutation located in the DNA-binding domain (5 patients with alopecia) and a novel p.T415R mutation located in the ligand-binding domain. A p.E143del CYP24A1 mutation, in the gene encoding the 25-hydroxyvitamin D3-24-hydroxylase, was identified in 2 brothers carrying the VDR gene mutation p.K45E. Six patients were treated with intermittent intravenous calcium treatment via the peripheral route with a clear improvement in 5 cases.

CONCLUSION

To the best of our knowledge, this is the first major series reporting on HVDRR in Tunisia. The same mutation (p.K45E) was found in 5 apparently unrelated affected individuals. We have also extended the mutation spectrum by studying 1 novel VDR mutation.

Transient neonatal diabetes mellitus and activating mutation in the KCNJ11 gene in two siblings

Transient neonatal diabetes mellitus is a rare disease usually associated with chromosome 6 abnormalities. Mutations of the genes encoding the potassium channel are rarely associated with these transitional forms. Herein, we report the clinical features of two siblings with a heterozygous mutation C679 G>A in the KCNJ11 gene.

[Unilateral to bilateral pleurisy: Pleural tuberculosis?]

Pleural tuberculosis is the first or second most common form of extrapulmonary tuberculosis as well as the main cause of pleural effusion in many countries. It is rare in young infants and is more common in children over 10 years of age. We report the case of a 19-month-old girl admitted for prolonged fever with unilateral pleural effusion. The mother reported a history of lymph node tuberculosis 6 years previously. Intravenous antibiotics with cefotaxime and vancomycin were started. Thoracocentesis yielded a serosanguinous exudate fluid with a lymphocyte predominance. The tuberculin skin test and PCR GeneXpert(©) on pleural fluid were negative. The initial outcome was favorable, but the chest X-rays 10 days after discharge showed bilateral pleural effusion. Pleural biopsy was proposed but the culture of pleural fluid was positive for Mycobacterium tuberculosis. The child was put under standard treatment for tuberculosis. The outcome was favorable.

Hemolytic anemia and metabolic acidosis: think about glutathione synthetase deficiency

Glutathione synthetase deficiency (GSSD) is a rare disorder of glutathione metabolism with varying clinical severity. Patients may present with hemolytic anemia alone or together with acidosis and central nervous system impairment. Diagnosis is made by clinical presentation and detection of elevated concentrations of 5-oxoproline in urine and low glutathione synthetase activity in erythrocytes or cultured skin fibroblasts. The prognosis seems to depend on early diagnosis and treatment. We report a 4 months old Tunisian male infant who presented with severe metabolic acidosis with high anion gap and hemolytic anemia. High level of 5-oxoproline was detected in her urine and diagnosis of GSSD was made. Treatment consists of the correction of acidosis, blood transfusion, and supplementation with antioxidants. He died of severe metabolic acidosis and sepsis at the age of 15 months.

Neonatal purulent meningitis in southern Tunisia: Epidemiology, bacteriology, risk factors and prognosis

OBJECTIVES

To study the epidemiological, clinical and bacteriological aspects and outcome of purulent neonatal meningitis (PNM).

METHODOLOGY

Retrospective analysis of 55 cases of PNM hospitalized in the pediatric ward of Hedi Chaker Hospital from 1990 to 2012. Infants less than 29 days of age were included. The diagnosis was made on either the presence of bacteria in the cerebrospinal fluid (CSF) or the combination of pleocytosis >30 cells/mm(3), protein level >1.3 g/l and glucose level <2.2 mmol/l or CSF/blood glucose ratio <0.4.

RESULTS

The male:female sex ratio was 1.75. One or more maternal risk factors for infection were found in 24 cases. The main symptoms were fever and poor feeding. Soluble antigen was positive in four cases and cultures had isolated the bacteria in 28 cases. The mortality rate was 40%. The sequelae rate in the survivors was 16.4%.

CONCLUSION

This study emphasizes the severity of PNM with high rates of mortality and neurological sequelae.

Molecular investigation of distal renal tubular acidosis in Tunisia, evidence for founder mutations

BACKGROUND

Distal renal tubular acidosis (dRTA) is a rare genetic disease caused by mutations in different genes involved in the secretion of H+ ions in the intercalated cells of the collecting duct. Both autosomal dominant and recessive forms have been described; the latter is also associated with sensorineural hearing loss.

METHODS

Twenty-two Tunisian families were analyzed for mutations in the ATP6V1B1 and ATP6V0A4 genes by direct sequencing. Dating of the founder mutations was performed.

RESULTS

Two founder mutations in the ATP6V1B1 gene were found in 16/27 dRTA cases. The p.Ile386Hisfs*56 founder mutation was estimated to be older than 2400 years and no correlations were found with deafness. For the remaining patients, two mutations in the ATP6V0A4 gene, one of them being novel, were found in three Tunisian cases. The presence of a heterozygous missense mutation p.T30I, of the ATP6V1B1 gene, was identified in six patients, while no mutations of the second gene were detected. No deleterious mutations of either ATP6V1B1 or ATP6V0A were found for the two probands.

CONCLUSION

Our study gives evidence of phenotypic and genotypic heterogeneity of dRTA in the Tunisian population. Five different mutations were found, two of them were due to a founder effect, and screening of these mutations could provide a rapid and valuable tool for diagnosis of dRTA.

Hemolytic anemia and progressive neurologic impairment: think about triosephosphate isomerase deficiency

We have reported the first Tunisian case of triosephosphate isomerase (TPI) deficiency in a 2-year-old girl. She was the first child of a nonconsanguineous couple. The disease included a neonatal onset of chronic hemolytic anemia, recurrent low-respiratory infections then progressive neurological involvement. The diagnosis was made after her death from the TPI values of her parents who exhibited intermediate enzyme deficiency. Molecular study of TPI genes showed that the father and the mother are heterozygous for Glu105Asp mutation. Pediatricians must be alert to the differential diagnosis in patients having hemolytic anemia and other concomitant manifestations.

[Hereditary hemorrhagic telangiectasia. Report of a pediatric case]

Hereditary hemorrhagic telangiectasia, or Rendu-Osler-Weber syndrome, is an autosomal dominant multiorgan disorder. This multisystemic vascular dysplasia is determined by a mutation of one of two main genes, endoglin (ENG) or HHT1, or ACVRL1 or HHT2. These mutations induce vascular disorders that cause recurrent epistaxis and eventually multiple telangiectasia and arteriovenous visceral malformations. We report the case of a 7-year-old girl who developed severe hypoxemia due to multiple pulmonary arteriovenous malformations.

[Primary immune thrombocytopenia in childhood: a regional study in the south of Tunisia]

BACKGROUND

the primary immune thrombocytopenia (ITP) in children has a favorable evolution in most of cases. aim: describe the epidemiological and therapeutic data and the outcome of primary immune thrombocytopenia in our patients and propose a treatment plan to standardize the management of this disease in our region. methods: We conducted a retrospective study of 140 cases of primary immune thrombocytopenia collected in department of pediatrics and hematology of Hedi Chaker hospital during a period of 15 years. Patients who had a platelet count ≤ 20 000 and / or mucosal or troublesome lifestyle hemorrhage were treated. results: The mean age was 6 years 7 months with extremes varying from 3 months to 15 years. The bleeding manifestations were dominated by cutaneous bleeding in the form of petechiae or bruise (100%). Epistaxis and gingivorragia were noted in 32,9% and 25,7% of the cases respectively. The most of patient were treated with corticosteroids (79%). Intravenous immunoglobulin was associated with corticosteroids in 7%. An acute ITP occurred in 94 cases (67%) and a chronic ITP in 30 cases (21%).

CONCLUSION

In the recently diagnosed ITP, the response delay under association Intravenous immunoglobulin and corticoids is shorter than that of corticoids alone, but the high cost of Intravenous immunoglobulin associated with their immediate side effects compels us to recommend corticoids as a first line of treatment.

[Bacterial meningitis in children: epidemiological data and outcome]

BACKGROUND

The bacterial meningitis in children remains a worrisome affection both by its frequency and by its gravity.

AIM

describe the epidemiological, clinical and evolutionary data of bacterial meningitis in children aged between 3 months and 15 years.

METHODS

we conducted a retrospective study of all cases of bacterial meningitis collected in the department of pediatrics of Hedi Chaker hospital, during a period of 6 years (2006-2011). We analyzed the files retrospectively and we studied the epidemiological data and the outcome.

RESULTS

Thirty cases of bacterial meningitis were recorded. The most frequent species were Streptococcus pneumoniae and Haemophilus influenzae followed by Neisseria meningitidis with respectively 43%, 40%, and 6% of cases. The yearly distribution of these bacteria showed an increase of the rate of the bacterial meningitis during the last 2 years. The average age of our patients was 1 year 6months (3 months-13 years). All the patients were vaccinated according to the Tunisian vaccination calendar; and none of them had pneumococcal vaccine or the Hib vaccine. The main clinical manifestations were fever (100 %), seizures (14 %) and vomiting (44 %). Bulging fontanel was noted in 15cas (55 %), somnolence in 11 cases (40 %) and axial hypotonia in 12 cases (44 %). In the outcome, the neurological sequelae were showed in eight patients (26%).

CONCLUSION

In our study, H. influenzae and S. pneumoniae were the main microorganisms responsible for bacterial meningitis. We strongly recommend the introduction pneumococcal vaccine in our vaccination calendar.

[Cerebral imaging in epileptic children: study of 140 cases]

BACKGROUND

Epilepsy is a chronic disease, often with an onset during childhood and characterized by spontaneous and recurrent seizures. It concerns 0.5-1% of children under 16 years of age. Being much more sensitive than computed tomography, magnetic resonance imaging is the technique of choice to identify an underlying cause. CT scan is used in emergency situations.

AIM

To describe cerebral lesions in epilepetic children and to identify predicative factors of abnormal neuroimaging.

METHODS

Authors present a retrospective descriptive study of Neuroimaging data of 140 epileptic children evaluated for a period from 2000-2007 in the paediatric departement of Sfax.

RESULTS

The mean age at onset of seizures was 3 years. The sex ratio was 1.12. Psychomotor retardation was noted in 75 patients. The seizures were generalized in 75% of case. Neurological examination was abnormal in 73 cases (52%). The main indications for conducting a brain imaging were psychomotor retardation (65 cases) and focal onset seizures (25 cases). Anoxo-ischemic lesions were the most frequent cerebral anomalies followed by brain malformations. Predictors of pathological MRI were an age at onset of seizure <3 years, psychomotor retardation and abnormal neurological examination.

CONCLUSION

The morphological imaging is recommended for recent seizures of the child with the exception of idiopathic epilepsies. MRI is the best imaging modality in exploration of epilepsy in this context.

[Primary distal renal tubular acidosis in children in the South of Tunisia: study of 15 cases]

BACKGROUND

primary distal renal tubular acidosis in children (RTA) is characterized by metabolic acidosis due to defect in urinary excretion of hydrogen (H+) in the distal tubular.

AIM

To report the epidemiological, clinical, therapeutic and evolutionary of distal RTA in our patients.

PATIENTS AND METHODS

We conducted a retrospective study of all cases of distal RTA collected in the department of pediatrics of Hedi Chaker University hospital in the south of Tunisia, during a period of 23 years (1988-2010). We studied the epidemiological, clinical, biological, evolutionary and therapeutic data.

RESULTS

During the study period 15 cases of distal RTA were collected. The average age was 6 months (1 month -2 years). Most common presenting symptoms were vomiting (8cases), failure to thrive (4cases), lack of appetite, polyuria-polydipsia syndrome (1case) and urinary infection (2cases). The clinical examination showed staturoponderal delay (9 cases), dehydration (6 cases), signs of rickets (3 cases) and polyuria (10 cases). Biological data showed high urine pH in the presence of metabolic acidosis in 11 cases, hypokalaemia in 10 cases and hypercalciuria in all cases. Urine acidification test with ammonium chloride was performed in 4 cases, the urinary pH was always higher than 5.5 in all cases. Ammoniuria performed in 9 cases was less than 40mmol/l. Radiological investigation objectified a nephrocalcinosis in fourteen patients and signs of rickets in three cases. Deafness was found in three patients. Genetic study performed in two cases showed mutation of ATP6V1B1 gene. The medical treatment involved an alkali load. Long-term outcome was favorable in 7 cases.

CONCLUSION

The distal renal tubular acidosis is a rare pathology in our country but probably under diagnosed. The clinical gravity of this disease and the risk of evolution towards the terminal renal insufficiency justify an antenatal diagnosis to establish a neonatal management or propose a therapeutic interruption of the pregnancy if the distal RTA is associated with a severe pathology.

Nephropathic infantile form of cystinosis about one case

Cystinosis is the major cause of inherited Fanconi syndrome, and should be suspected in young children with a failure to thrive and with signs of renal proximal tubular damage. This is a study of a case report of cystinosis revealed by a growth failure and chronic dehydration. A 9-month-old boy was referred to our department for evaluation of polyuria and polydipsia. Clinical examination showed dehydration and enlarged wrists and rachitic rosaries. The presence of metabolic acidosis, hypokalemia, hypochloremia with proteinuria, polyuria, and hypercalciuria was suggestive of inherited Fanconi syndrome. The diagnosis of cystinosis was confirmed by an increased leukocyte cystine level.

[Primary immunodeficiency disorders in 51 cases]

BACKGROUND

Primary immunodeficiency disorders (PID) are a heterogeneous group of diseases, characterized by an increased susceptibility to infections.

AIM

To determine the frequency of PID in south of Tunisia to collect information on clinical experience with these disorders.

METHODS

Over a period of 16 years (1995 - 2010), primary immunodeficiency was confirmed in 51 patients (31 boys and 20 girls). The immunological investigation included a study of specific and/or non specific humoral and cellular immunity.

RESULTS

These 51 patients belonged to 47 families among which 37 were consanguine (80%). The immunological investigations revealed a cellular or combined immunodeficiency in 21 cases, with a majority of ataxia-telangiectasia syndromes (11 cases), HLA class II deficiency (9 cases). A predominant antibody defect was found in 3 patients and a chronic granulomatous disease in seven cases. Deaths occurred So far in 19 patients (37 %).

CONCLUSIONS

PID are relatively frequent in Tunisia, probably because of the high rate of consanguinity among the general population. The distribution of the different groups of primary immunodeficiencies is characterized by high frequency of ataxia - telangiectasia and HLA class II deficiency.

New trends to support independence in persons with mild dementia: a mini-review

Our research was motivated by the growing aging population worldwide and the need to concentrate research efforts on a specific target group; it focuses on elderly persons with physical and cognitive deficiencies. The primary goal is to enable persons with mild dementia to maximize their physical and mental functions through assistive technologies in order to be able to continue to participate in social networks and lead independent and purposeful lives. Persons with mild dementia usually have problems in performing activities of daily living due to episodic memory decline. These can include simple activities, such as bathing, changing clothes and preparing meals. Through extended field test trials involving end users, we have demonstrated that assistive technology that provides timely prompts, alarms and reminders can enable them to preserve their abilities and improve their quality of life. Understanding the user context, especially when targeting demented individuals, and providing the required personalized assistive services is the objective of our research work. Finding the appropriate user interface to interact with the provided services is often a barrier. Thus, we have adopted the approach of a multimodal interactive system with the living environment including a TV set, iPad-like tablets, sensors/actuators, and wireless speakers connected to a reasoning engine that is able to consider the complexity of the users' profile defined by his/her cognitive abilities. In this paper we will mainly focus on the interaction level with the system as well as on the validation stages performed to meet the users' requirements. This is the result of several years' work since 2006 in the frame of two projects (IST-FP6 COGKNOW European completed project and AMUPADH ongoing project in Singapore).

How MRI can contribute to the diagnosis of acute demyelinating encephalomyelitis in children

OBJECTIVE

To illustrate through 10 pediatric cases, the clinical features, course, and importance of neuroimaging (especially MRI) in guiding the diagnosis of acute disseminated encephalomyelitis (ADEM) and controlling patients after treatment.

METHODS

A retrospective review of 10 pediatric cases of ADEM, with special regard to the MRI features, presenting to the Pediatric Departments, Hedi Chaker Hospital, Sfax, Tunisia between January 2002 and December 2008.

RESULTS

Children with ADEM presented with variable and multiple neurological signs most often occurring after an infectious episode, especially after upper respiratory tract infection. The MRI permitted confirmation of the diagnosis by showing demyelinating lesions either in the brainstem, the cerebellum, the cerebral white and grey matter, or in the spine of all patients.

CONCLUSION

Acute disseminated encephalomyelitis is characterized by multifocal demyelinating lesions resulting in varied neurological signs. The MRI is the technique of choice to show these lesions.

[Bardet - Biedl syndrome in the child. A study of 11 cases]

BACKGROUND

The syndrome of Bardet-Biedl is definite clinically by the association of obesity, polydactyly, pigmentary retinopathy, hypogonadism and backwardness.

AIM

To study the epidemiologic, clinical, biological, genetic, therapeutic and evolutionary characteristic of our patients.

METHODS

We carried out a retrospective study concerning 11 hospitalized children and/or follow-ups with the service of pediatry of the CHU Hédi Chaker of Sfax for syndrome of Bardet-Biedl during a period of 21 years (1987-2007).

RESULTS

The obesity was constant among all patients, polydactyly was found in 9 cases, the fall of night vision in 7 cases. The hypogonadism was constant among all our boys. The bottom of eye was practised among 9 patients, it showed a pigmentary aspect of retinopathy among 8 patients. The electroretinogram was done in 10 patients, it showed a pigmentary retinopathy in all the cases. The radiological exploration of the urinary tract made it possible to identify morphological anomalies in 3 cases. The genetic study concerned the families of one of our patients and it allowed the identification of a new gene BBS8 at one of the families. Treatment was only symptomatic. After 6 years an average retreat, we noted an aggravation of obesity (9cas) and visual deficit (7cas). Only one patient evolved to the chronic renal insufficiency.

CONCLUSION

The syndrome of Bardet-Biedl is a hereditary disease characterized by a genetic heterogeneity. The diversity of the systemic attacks defining this syndrome is a source of several handicaps: blindness, backwardness and obesity. The forecast is conditioned by the renal attack of or the interest of an early tracking and genetic council.

[Hypoplasia of the internal carotid artery: a rare cause of cerebral ischemic stroke in children]

Hypoplasia of the carotid arteries is a rare congenital anomaly which, when symptomatic, presents as cerebral ischemia or hemorrhage. We report a case of hypoplasia of the carotid arteries revealed by cerebral ischemic stroke in an infant with hereditary spherocytosis. The diagnosis was confirmed by MR angiography. We describe this rare cause of stroke in children and the characteristics of its association with hereditary spherocytosis.

[Type I Crigler Najjar syndrome in Tunisia: a study of 30 cases]

BACKGROUND

Crigler-Najjar syndrome is a rare metabolic disorder characterized by severe unconjugated hyperbilirubinemia resulting in deficiency of bilirubin uridine diphosphate (UDP) glucuronosyltransferase activity in the liver.

AIM

To study the clinical, genetic therapeutic aspects and the outcome of Crigler Najjar type 1 in Tunisia.

METHODS

This is a retrospective report of Crigler Najjar cases who were hospitalised in pediatric department of Hédi Chaker hospital during 21 years (from 1st January to 31 December 2006).

RESULTS

Our study included 30 cases of Crigler-Najjar syndrome; there were 10 females and 20 males (sex ratio = 2). The mean age of our patients was 41 days (4 days - 9 months). All patients were presented with intense jaundice. Sixteen patients had neurologic disorders since admission. Genetic analysis was performed in 9 patients; we identified the same mutation in all cases: -C1070>G in exon 3 of the UDP glucuronyl transferase. Concerning therapeutic measurements, conventional phototherapy was used in all patients. A fatal out come was observed in 28 case; they died of kernicterus.

CONCLUSION

Crigler-Najjar syndrome is a serious disorder which, when not treated, ultimately leads to brain damage (bilirubin encephalopathy) and death. That's why we must promote prenatal diagnosis and genetic council especially because of the big frequency of consanguinity in our country.

A case of Kearns-Sayre syndrome with two novel deletions (9.768 and 7.253 kb) of the mtDNA associated with the common deletion in blood leukocytes, buccal mucosa and hair follicles

Kearns-Sayre syndrome is a mitochondrial disorder characterized by the emergence before the age of 20 years of progressive external ophthalmoplegia, pigmentary retinopathy, with other heterogeneous clinical manifestations. Generally, mitochondrial DNA deletions were associated with KSS but the size and position of these deletions differ among patients. This study reported a Tunisian patient with typical features of KSS. Long-range PCR amplification of the mtDNA in different tissues from this patient showed multiple mitochondrial deletions: two novel 9.768 and 7.253 kb deletions spanning respectively nucleotides 6124-15,893 and 8572-15,826 associated with the common 4.977 kb deletion.

[Cholelithiasis associated with portal cavernoma in children: 2 case reports]

The association of cholelithiasis and portal cavernoma is rarely described in adult or pediatric patients. We report 2 cases of gallstone associated with portal cavernoma in 2 girls. The first one suffered from Evans syndrome associated with congenital immune deficiency. The portal cavernoma was discovered with gallstone after splenectomy indicated because of high steroid dependence. In the second case, the cavernoma complicated neonatal umbilical catheterism. The gallstone was asymptomatic and discovered on annual ultrasonography. Septicemia, profound thrombocytopenia, and acute anaemia led to rapid death in the first case. However, the progression was favourable under celioscopic treatment in the second one. Our original observations suggest systematically searching for gallstone in children with portal cavernoma.

Two new mutations in the MT-TW gene leading to the disruption of the secondary structure of the tRNA(Trp) in patients with Leigh syndrome

Leigh syndrome is a progressive neurodegenerative disorder occurring in infancy and childhood characterized in most cases by a psychomotor retardation, optic atrophy, ataxia, dystonia, failure to thrive, seizures and respiratory failure. In this study, we performed a systematic sequence analysis of mitochondrial genes associated with LS in Tunisian patients. We sequenced the encoded complex I units: ND2, ND3, ND4, ND5 and ND6 genes and the mitochondrial ATPase 6, tRNA(Val), tRNA(Leu(UUR)), tRNA(Trp) and tRNA(Lys) genes in 10 unrelated patients with Leigh syndrome. We revealed the presence of 34 reported polymorphisms, nine novel nucleotide variants and two new mutations (T5523G and A5559G) in the tested patients. These two mutations were localized in two conserved regions of the tRNA(Trp) and affect, respectively, the D-stem and the T-stem of the mitochondrial tRNA leading to a disruption of the secondary structure of this tRNA. SSP-PCR analysis showed that the T5523G and A5559G mutations were present with respective heteroplasmic rates of 66% and 43 %. We report here the first mutational screening of mitochondrial mutations in Tunisian patients with Leigh syndrome which described two novel mutations associated with this disorder.