Congenital surfactant protein B (SP-B) deficiency: a case report.

The incapacity to synthesize certain components of pulmonary surfactant causes a heterogeneous group of rare respiratory diseases called genetic disorders of surfactant dysfunction. We report a female full-term infant with neonatal respiratory distress of early onset due to inherited SP-B deficiency. The infant failed oxygen weaning at multiple trials. Chest computed tomography was performed on the 29th day of life revealing ground-glass opacities, regular interlobular septal thickening and fine interlobular reticulations. Analysis of genomic DNA showed homozygosity for an extremely rare SFTPB gene variant (c.620A>G, p.Tyr207Cys). Both parents were heterozygotes for the mutation. The diagnosis of congenital SP-B deficiency should be suspected whenever an early and acute respiratory failure in a term or near-term infant does not resolve after five days of age: diagnostic confirmation can be easily and rapidly obtained with the analysis of genomic DNA.

Spontaneous intrapleural rupture of mediastinal teratoma in child.

Introduction: Mediastinal teratomas are rare in children. Nevertheless, they represent the most frequent mediastinal germ cell tumor. Most often, they are discovered incidentally in older children or adolescents on chest X-ray. There are other signs of discovery but less frequent: chest pain, hemoptysis and signs of mediastinal compression. Rupture into pleural space, pericardium or tracheobronchial tree are exceptional. Case presentation: We report the case of 7-years old girl admitted for chest pain. The chest x-ray showed a mediastinal mass with calcifications and pleural effusion. Chest CT scan revealed a well limited heterogeneous anterior mediastinal mass with calcifications and a left pleural effusion. She underwent a median sternotomy and the tumor was completely excised. Histopathology confirmed the diagnosis of mature teratoma. Conclusion: Intrapleural rupture is a rare complication of mature teratoma. Calcifications on chest imaging in afebrile children with pleural effusion should be suspected of mediastinal teratoma.

Association analysis of the surfactant protein-C gene to childhood asthma.

OBJECTIVES: This study aims to describe the molecular variability in the SFTPC gene in a childhood chronic respiratory disease, asthma, in the Tunisian population and to identify the implications based on a case-control study of p.Thr138Asn (T138N) and p.Ser186Asn (S186N) variants. METHODS: We used direct sequencing for the genotyping of the SFTPC gene within 101 asthmatic children. The study of T138N and S186N variants in 110 controls is conducted by the PCR-RFLP technique. RESULTS: The molecular study revealed 26 variants including 24 intronic variations and 2 exonic variations (T138N and S186N) with respective frequencies of 16.8% and 18.3%. We conducted a case-control study of the two identified exonic variations. A different genotypic and allelic distribution between the two groups was noted. Only the T138N polymorphism showed a significant association with asthma disease (p < 1 0 -3). Statistical analysis elaborated four haplotypes with the following frequencies in patients vs controls: 138Thr-186Ser (79.5% vs 57.6%), 138Thr-186Asn (3.7% vs 7.8%), 138Asn-186Thr (2.2% vs 20.2%) and 138Asn-186Asn (14.6% vs 14.4%). A significant difference (p < 1 0 -3) was highlighted in haplotype distribution. The 138Asn-186Ser (OR [95%CI] = 0.14[0.04-0.54], p = 0.004, R2=0.93) and 138Thr-186Asn (OR [95%CI] = 0.35[0.12-0.54], p = 0.047, R2=0.88) haplotypes showed a negative association with asthma which may constitute a protective factor against the disease. CONCLUSION: In Tunisia, this work constitutes the first report interested in the SFTPC gene and highlights the genetic variability of the SFTPC gene in asthma. Therefore, the case-controls analysis may be useful in the study of surfactant proteins dysfunction in chronic respiratory disease at an early age.

Contribution of common CFTR variants (M470V, T854, and Q1463) to cystic fibrosis in Tunisia: haplotype analysis.

BACKGROUND & OBJECTIVES: Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF transmembrane regulator (CFTR) protein, a chloride channel located in the epithelial cell membrane. Over than 2,000 CFTR mutations have been identified, which contribute to the variety of clinical phenotypes of CF. We performed a case-control study to determine p.Met470Val (M470V), p.Thr854= (T854) and p.Gln1463= (Q1463) polymorphisms frequencies in CF patients and healthy controls and to elaborate haplotype based on these SNPs. METHODS: The genotyping of M470V (exon 10), T854 (exon 14a), and Q1463 (exon 24) variants were identified using polymorphism restriction fragment length polymorphism (RFLP). RESULTS & CONCLUSION: Statistical difference was noted in the genotype distribution of two markers, M470V and T854, between CF and control groups. However, the Q1463 polymorphism is not identified in two studied groups. Three haplotypes were found in CF patients and controls. An exclusive association between the ancestral haplotype 1-1-2 and p.Phe508del (F508del) mutation was shown. In Tunisia, this is the first work to be interested in the analysis of M470V, T854 and Q1463 polymorphisms and haplotypes associated with the most common mutation, F508del, in the Tunisian population and worldwide.

Molecular characterization of respiratory syncytial virus circulating in Tunisia between 2015 and 2018.

Introduction. Respiratory syncytial virus (RSV) is the most frequently identified viral agent in children with lower respiratory tract infection (LRTI). No data are available to date regarding RSV genotypes circulating in Tunisia.Aim. The aim of the present study was to investigate the genetic variability of the glycoprotein G gene in Tunisian RSV strains.Methodology. Nasopharyngeal aspirates were collected from infants hospitalized for LRTI in five Tunisian hospitals. All specimens were screened for RSV by a direct immunofluorescence assay (DIFA). To molecularly characterize Tunisian RSV strains, a phylogenetic analysis was conducted. Randomly selected positive samples were subjected to reverse transcription PCR amplifying the second hyper-variable region (HVR2) of the G gene.Results. Among a total of 1417 samples collected between 2015 and 2018, 394 (27.8 %) were positive for RSV by DIFA. Analysis of 61 randomly selected RSV strains revealed that group A RSV (78.7 %) predominated during the period of study as compared to group B RSV (21.3 %). The phylogenetic analysis showed that two genotypes of RSV-A were co-circulating: the ON1 genotype with a 72-nt duplication in HVR2 of the G gene was predominant (98.0 % of RSV-A strains), while one RSV-A strain clustered with the NA1 genotype (2.0 %). Concerning Tunisian group B RSV strains, all sequences contained a 60-nt insertion in HVR2 and a clustered BA10 genotype.Conclusion. These data suggest that RSV-A genotype ON1 and RSV-B genotype BA10, both with duplications in the G gene, were widely circulating in the Central coastal region of Tunisia between 2015 and 2018.

Cystic fibrosis in Tunisian children: a review of 32 children.

BACKGROUND: Cystic fibrosis is rare in Tunisia. Its diagnosis requires experienced specialists. Its prognosis is poor in developing countries. OBJECTIVES: To study the epidemiologic, clinical, genetic features and the therapeutic challenges of cystic fibrosis in Tunisian children. METHODS: Covering a period of 21 years, this retrospective study included all patients with a definite diagnosis of cystic fibrosis from the Pediatrics Department B of The Children's Hospital of Tunis. RESULTS: Data from 32 children (14 boys and 18 girls) were collected. The diagnosis was made during the first year of life in 28 cases. Meconium ileus was found in 5 cases, respiratory manifestations in 22 cases, chronic diarrhea in 19 cases, faltering growth in 17 cases and a pseudo Barter syndrome in 2 cases. The sweat chloride test was positive in all cases. The most frequent mutation was F508del (56% of cases). Respiratory complications marked the outcome. Among our 32 patients, 15 patients (50%) died at an average age of 5 years and 3 months, mainly due to respiratory failure. The mean age of the surviving patients was 5 years. CONCLUSION: Cystic fibrosis prognosis is poor in our series compared to developed countries due to the longer diagnostic delay and the limited therapeutic options.

[Community-acquired pneumonia due to Panton-Valentine producing Staphylococcus aureus: first description in Tunisia]. / Pneumonie communautaire à Staphylococcus aureus producteur de la toxine de Panton-Valentine: première description en Tunisie.

BACKGROUND: Community-acquired pneumonia due to Panton-Valentine producing S.aureus is a serious infection recently described. Many cases have been reported worldwide. AIM: We report here the first case in Tunisia. OBSERVATION: Our patient is a previously healthy fourteen-year-old girl hospitalized for bilateral hypoxemic pneumonia. The clinical course had violently deteriorated two hours later, marked by massive hemoptysis that lead to rapid degradation of her hemodynamic state and death. Toxicologic research and bloodcultures were negatives. A post-mortem pleural specimen culture yielded a meticillin-resistant Staphylococcus aureus strain that carried the Panton-Valentine leucocidin genes. CONCLUSION: Community-acquired pneumonia due to Panton-Valentine producing Staphylococcus aureus is a serious affection unrecognized in our country. Thus, this pathogen must imperatively be included in the spectrum of those responsibles for pulmonary infections in children and young adults