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.

Hemophagocytic Lymphohistiocytosis: A Rare Complication of an Ultrarare Lysosomal Storage Disease.

Hemophagocytic lymphohistiocytosis (HLH) is a rare and life-threatening hyperinflammatory condition that may be triggered by infections, autoimmune and immunologic disorders, malignancies, and metabolic diseases. Early and accurate diagnosis of HLH and its underlying cause is of paramount importance for proper management and prognosis. We report the case of a Tunisian 21-month-old girl who initially presented clinical features of HLH related to a lysosomal acid lipase deficiency. The genetic sequence analysis of the LIPA gene revealed a never described homozygous mutation c.966G>C (p.Gln322His). The parents were heterozygous for this mutation. Enzyme replacement therapy was not provided for the patient. She received etoposide, corticosteroids, and cyclosporine for the HLH. She is waiting for hematopoietic stem cell transplantation. To the best of our knowledge, this is the second Tunisian case of secondary HLH complicating lysosomal acid lipase deficiency related to a new homozygous mutation: c.966G>C (p.Gln322His).

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.

[Rheumatic cardiopathies and its risk factors: about 50 cases]. / Les complications cardiaques du rhumatisme articulaire aigu et ses facteurs de risque : étude de 50 observations.

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.

Resistant invasive aspergillosis in an autosomal recessive chronic granulomatous disease.

Chronic granulomatous disease (CGD) is an inherited immunodeficiency characterized by severe bacterial and fungal infections. Invasive aspergillosis and other rare mold diseases are the leading causes of mortality. We report one case of CGD revealed by retropharyngeal abscess. On evolution, the patient developed an invasive aspergillosis resistant to treatment.

Miliary tuberculosis mimicking COVID-19 multisystemic inflammatory syndrome in children.

Miliary tuberculosis (TB) is a severe form of disseminated TB. In pediatrics, many cases are missed because the symptomatology of TB mimics common childhood diseases. We present the case of a 6-year-old girl with no remarkable history who had recurrent fever for 3 months. She was initially diagnosed with, and treated for, refractory multisystem inflammatory syndrome in children (MIS-C). When the study was extended to other differential diagnoses, thoraco-abdominopelvic computed tomography revealed miliary pulmonary nodules in addition to lymph nodes and spleen lesions. Magnetic resonance imaging of the brain revealed multiple tuberculomas. The tuberculin test results were positive. The course of the disease was favorable under quadruple therapy.

Febrile seizures: an epidemiological and outcome study of 482 cases.

INTRODUCTION: Febrile seizures (FSs) are the most common type of seizures seen in children. After the first FS, 3 to 12% of children develop epilepsy, and 30% of these patients present with recurrent FS. The purpose of this study was to describe the epidemiological aspects of FS in order to better define the long-term outcomes in children with first FS and to identify the risk factors associated with the recurrence of FS as well as the development of epilepsy. METHODS: A retrospective study of 482 children with FS was conducted from January of 2004 to December of 2009 in the pediatric department of Hedi Chaker University Hospital in Sfax, Tunisia. The medical records for each patient were first collected and then analyzed at a later time. RESULTS: The study included 482 children. Simple FSs were found in 55.2% of children, and complex FSs were observed in 44.8%. The mean duration for follow-up examinations was 2 years and 4 months, and ranged from 1 to 5 years. No deaths or permanent neurological deficits due to FSs were observed, and only six children (1%) developed epilepsy. A total of 57 children (11.7%) developed recurrent seizures. Our findings suggest that a family history of FS, young age at onset, and a low degree of fever were predictive of recurrent FSs. CONCLUSION: Children with FSs encounter a minor risk of mortality and morbidity. While recurrent seizures are observed in these children, only a minority of these patients develop epilepsy.

Childhood asthma : factors predicting severity and persistence of symptoms.

BACKGROUND: Asthma is the most common chronic disease in infants. In young children, asthma still raises many questions and many points are still being debated. AIM: The aim of this study is to identifies, in asthmatic children, factors predictors of severity and persistence of symptoms. METHODS: A retrospective study of asthmatic infants<3 years enrolled in the pediatric department of Sfax over a period of 5 years (2007-2011). We were interested to social and environmental factors, the allergic background, clinical severity of the disease, results of allergic skin tests, treatment and respiratory outcome. RESULTS: We collected 180 children with a sex ratio of 2.2. Family history of atopy and exposition to passive tobacco were noted in 45 % and 52% of cases respectively. The mean age of onset of wheezing was 6.6 months. Skin tests were positives in 32% of cases. At the time of diagnosis, asthma was classified intermittent (21%), mild to moderate (55.6%) and severe (22.2%).  Inhaled corticosteroids was initiated in 142 infants (78.8%). Skin tests performed in 84 patients, were positive in 32%. Factors associated with severe asthma were passive smoking, early age of onset, number of hospitalizations for exacerbation and existence of an aggravating factor. Factors predictors of persistence were an early age of onset, caesarean delivery, passive smoking and positive skin tests. CONCLUSION: Factors associated with persistence of asthma at the individual level remains uncertain. However, atopy and passive smoking are major indicators.

Copy-number variation of the NPHP1 gene in patients with juvenile Nephronophthisis.

Objective: Juvenile nephronophthisis (NPHP) is an autosomal recessive cystic disease of the kidney. It represents the most frequent genetic cause of chronic renal failure in children. Methods: we investigated clinical and molecular features in two children with Juvenile nephronophthisis using firstly Multiplex ligation-dependent probe amplification (MLPA) and secondly multiplex PCR. Results: we report a homozygous NPHP1 deletion in two children. Conclusion: NPHP1 deletion analysis using diagnostic methods (e.g. MLPA, Multiplex PCR) should always be considered in patients with nephronophthisis, especially from consanguineous families. Our results provide insights into genotype-phenotype correlations in juvenile nephronophthisis that can be utilized in genetic counseling.

[Epidemiology of home accidents in childhood: experience in the Division of General Pediatrics in Southern Tunisia]. / Epidémiologie des accidents domestiques de l'enfant: expérience d'un Service de Pédiatrie Générale du sud tunisien.

Home accidents are a serious public health problem in Pediatrics. They are responsible for heavy morbidity and mortality in the paediatric population. We conducted a retrospective study of 231 cases of domestic accidents in childhood in the Division of General Pediatrics at the Hedi Chaker Hospital, Sfax over a period of 5 years (2008-2012). During the study period, we collected data from 231 domestic accidents. The study involved 124 boys (53.7 %) and 107 girls (46.3%). The average age of patients was 2 years, ranging from 1 day to 14 years; children under 4 years were the most exposed to home accidents (88.7%). Accidental poisonings were the most common accidents (105 cases). Caustics were the most common toxic agents (33 cases), followed by drugs (28 cases) and hydrocarbons (16 cases). Foreign body accidents were the second most common mechanism of injury (64 cases). They included 43 cases of inhalation of foreign bodies and 21 cases of foreign body ingestion. We recorded 28 cases of trauma, 25 cases were caused by a fall from a certain height. We noted 26 cases of scorpion envenomation, 5 cases of drowning, 2 cases of burn and a single case of electric shock. Accidental poisonings and foreign body accidents were the main home accidents noted during our study and the age group 1 -4 years was the most exposed to home accidents.

Factor XIII deficiency in south of Tunisia.

: Factor XIII deficiency is a rare autosomal recessive disorder of hemostasis characterized by a plasmatic factor XIII level less than 1% in homozygote and bleeding as of the youth. The aim of the study is to describe the clinical features and the outcome of the patients and to determine molecular characteristics. A retrospective study, was conducted on seven patients with factor XIII deficiency in the department of hematology and pediatrics, Hedi Chaker Hospital, Sfax, Tunisia during the period of 14 years (2001-2014). The activity of factor XIII in plasma of the patients was less than 1%. Seven patients from five unrelated families were recorded (four men and three women). Median age at diagnosis was 3.5 years. All patients had consanguineous parents. Six patients presented umbilical bleeding and only three patients had intracranial bleeding. Other bleeding features were seen, including skin and mucosal bleeding, muscular hematoma, and splenic rupture. Recurrent abortions were observed in one patient. The standard screening tests were normal. Genetic analysis identified two mutations interesting the subunit A of factor XIII. All patients received transfusion of fresh frozen plasma monthly. One patient was died because of intracranial hemorrhage.Factor XIII deficiency is a rare bleeding disorder which frequently increases in areas with high consanguinity. In our study, we identified a founder mutation. The prognosis of the disorder is related to hemorrhagic complications especially to life-threatening intracranial bleeding. Prophylaxis consists of factor XIII concentrate or recombinant factor XIII. If these are unavailable, fresh frozen plasma may be used.

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.