Primary ciliary dyskinesia gene contribution in Tunisia: Identification of a major Mediterranean allele.

Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disease of motile cilia. Even though PCD is widely studied, North-African patients have been rarely explored. In this study, we aim at confirming the clinical diagnosis and explore the genetic spectrum of PCD in a cohort of Tunisian patients. Forty clinically diagnosed patients with PCD belonging to 34 families were recruited from Tunisian pediatric departments. In each proband, targeted capture PCD panel sequencing of the 40 PCD genes was performed. PCD panel sequencing identified bi-allelic mutations in 82% of the families in eight PCD genes. Remarkably, 23.5% of patients carried the same c.2190del CCDC39 mutation. Single nucleotide polymorphism profiling in six unrelated patients carrying this mutation has revealed a founder effect in North-African patients. This mutation is estimated to date back at least 1,400-1,750 years ago. The identification of this major allele allowed us to suggest a cost-effective genetic diagnostic strategy in North-African patients with PCD.

Poikiloderma with neutropenia in a Tunisian patient with a novel C16orf57 gene mutation.

Poikiloderma with neutropenia (PN) is a genodermatosis characterized by poikiloderma, permanent neutropenia, recurrent infections, nail abnormalities, and palmoplantar hyperkeratosis. We report the case of a Tunisian patient with PN. Skin lesions started from the face and spread to the extremities and trunk. Neutropenia was initially periodic and concomitant with infections periods. DNA analysis identified a novel homozygous deletion of a 1-bp (c.161delC, p.P54RfsX60) in the C16orf57gene, presumed to be causative. This report presents the variability of the clinical manifestations and evolution of PN and emphasizes the importance of studying other patients with PN to better delineate mutations profile among populations.

Novel and recurrent AID mutations underlie prevalent autosomal recessive form of HIGM in consanguineous patients.

Immunoglobulin class switch recombination deficiencies (Ig-CSR-D) are characterized by normal or elevated serum IgM level and absence of IgG, IgA, and IgE. Most reported cases are due to X-linked CD40L deficiency. Activation-induced cytidine deaminase deficiency is the most frequent autosomal recessive form, whereas CD40 deficiency is more rare. Herein, we present the first North African study on hyper IgM (HIGM) syndrome including 16 Tunisian patients. Phenotypic and genetic studies allowed us to determine their molecular basis. Three CD40LG mutations have been identified including two novels (c.348_351dup and c.782_*2del) and one already reported mutation (g.6182G>A). No mutation has been found in another patient despite the lack of CD40L expression. Interestingly, three AICDA mutations have been identified in 11 patients. Two mutations were novel (c.91T>C and c.389A>C found in one and five patients respectively), and one previously reported splicing mutation (c.156+1T>G) was found in five patients. Only one CD40-deficient patient, bearing a novel mutation (c.109T>G), has been identified. Thus, unlike previous reports, AID deficiency is the most frequent underlying molecular basis (68%) of Ig-CSR-D in Tunisian patients. This finding and the presence of specific recurrent mutations are probably due to the critical role played by inbreeding in North African populations.

Report of the Tunisian Registry of Primary Immunodeficiencies: 25-Years of Experience (1988-2012).

PURPOSE: Primary immunodeficiencies (PIDs) are a large group of diseases characterized by susceptibility to not only recurrent infections but also autoimmune diseases and malignancies. The aim of this study was to describe and analyze the distribution, clinical features and eventual outcome of PID among Tunisian patients. METHODS: We reviewed the record of 710 patients diagnosed with Primary Immunodeficiency Diseases (PIDs) from the registry of the Tunisian Referral Centre for PIDs over a 25-year period. RESULTS: The male-to-female ratio was 1.4. The median age at the onset of symptoms was 6 months and at the time of diagnosis 2 years. The estimated prevalence was 4.3 per 100,000 populations. The consanguinity rate was found in 58.2 % of families. According to the International Union of Immunological Societies classification, spectrums of PIDs were as follows: combined T-cell and B-cell immunodeficiency disorders account for the most common category (28.6 %), followed by congenital defects of phagocyte (25.4 %), other well-defined immunodeficiency syndromes (22.7 %), predominant antibody deficiency diseases (17.7 %), diseases of immune dysregulation (4.8 %), defect of innate immunity (0.4 %) and complement deficiencies (0.4 %). Recurrent infections, particularly lower airway infections (62.3 %), presented the most common manifestation of PID patients. The overall mortality rate was 34.5 %, mainly observed with combined immunodeficiencies. CONCLUSION: The distribution of PIDs was different from that reported in Western countries, with a particularly high proportion of Combined Immunodeficiencies and phagocyte defects in number and/or function. More is needed to improve PID diagnosis and treatment in our country.

Antioxidant enzymes activities in obese Tunisian children.

BACKGROUND: The oxidant stress, expected to increase in obese adults, has an important role in the pathogenesis of many diseases. It results when free radical formation is greatly increased or protective antioxidant mechanisms are compromised. The main objective of this study is to evaluate the antioxidant response to obesity-related stress in healthy children. METHODS: A hundred and six healthy children (54 obese and 52 controls), aged 6-12 years old, participated in this study. The collected data included anthropometric measures, blood pressure, fasting glucose, total cholesterol, triglycerides and enzymatic antioxidants (Superoxide dismutase: SOD, Catalase: CAT and Glutathione peroxidase: GPx). RESULTS: The first step antioxidant response, estimated by the SOD activity, was significantly higher in obese children compared with normal-weight controls (p < 0.05). Mean activities of anti-radical GPx and CAT enzymes were not affected by the BMI increase. Although, total cholesterol levels were statistically higher in the obese group, there was no significant association with the SOD activity. CONCLUSIONS: The obesity-related increase of the oxidant stress can be observed even in the childhood period. In addition to the complications of an increased BMI, obesity itself can be considered as an independent risk factor of free radical production resulting in an increased antioxidant response.

Preliminary national report on cystic fibrosis epidemiology in Tunisia: the actual state of affairs.

AIM: To establish a preliminary national report on clinical and genetic features of cystic fibrosis (CF) in Tunisian children as a first measure for a better health care organization. METHODS: All children with CF diagnosed by positive sweat tests between 1996 and 2015 in children's departments of Tunisian university hospitals were included. Data was recorded at diagnosis and during the follow-up from patients' medical records. RESULTS: In 12 departments, 123 CF children were collected. The median age at diagnosis was 5 months with a median diagnosis delay of 3 months. CF was revealed mostly by recurrent respiratory tract infections (69.9%), denutrition (55.2%), and/or chronic diarrhea (41.4%). The mean sweat chloride concentration was 110.9mmol/L. At least one mutation was found in 95 cases (77.2%). The most frequent mutations were Phe508del (n=58) and E1104X (n=15). Fifty-five patients had a Pseudomonas Aeruginosa chronic colonization at a median age of 30 months. Cirrhosis and diabetes appeared at a mean age of 5.5 and 12.5 years respectively in 4 patients each. Sixty-two patients died at a median age of 8 months. Phe508del mutation and hypotrophy were associated with death (p=0.002 and p<0.001, respectively). CONCLUSION: CF is life-shortening in Tunisia. Setting-up appropriate management is urgent.

[Severe community acquired pneumonia due to Staphylococcus aureus in children. About two cases]. / Pneumonies staphylococciques graves de l'enfant. A propos de deux observations.

The staphylococcal pneumonia is the prerogative of the infant but rare cases were observed in the childhood. We report the observation of two children aged respectively of six years and three years and a half having presented a particular form of severe staphylococcal pneumonia apart from any context of immunodepression. The identification of the particular strains producing toxins Like the Panton and Valentine leukocidin constitutes the first stage of the comprehension of this atypical form of pneumonia. Through these observations and with a review of literature we underline the specific clinical and biological aspects of this form.

[Involved factors in stability of children's asthma. A study of 150 children in Mahdia]. / Les facteurs intervenant dans la stabilite de l'asthme de l'enfant. Etude de 150 enfants de la région de Mahdia.

In order to reduce the mortality and morbidity by asthma in perpetual increasing, taking in charge of asthmatic child must be general (therapeutic and educative) with the intention to stabilize il cause of the lack of curing ait. The aim of our work was to determinate the factors in stability of asthma. Our study was retrospective, inducing 150 asthmatic children regularly observed since at least 6 months and more than 4 years old: 77 of them was judged stable and 73 unstable. Stable asthma concerned insignificatively children who are more than 8 year old, from urban areas, unexposed to tobacco living is sunny homes and when there is no associated factors like effort asthma and gastro-oesophagien reflux. Instability of asthma has been in significantly correlated with the initial severity and non adaption to treatment.