Loss-of-Function Mutations in UNC45A Cause a Syndrome Associating Cholestasis, Diarrhea, Impaired Hearing, and Bone Fragility.

Despite the rapid discovery of genes for rare genetic disorders, we continue to encounter individuals presenting with syndromic manifestations. Here, we have studied four affected people in three families presenting with cholestasis, congenital diarrhea, impaired hearing, and bone fragility. Whole-exome sequencing of all affected individuals and their parents identified biallelic mutations in Unc-45 Myosin Chaperone A (UNC45A) as a likely driver for this disorder. Subsequent in vitro and in vivo functional studies of the candidate gene indicated a loss-of-function paradigm, wherein mutations attenuated or abolished protein activity with concomitant defects in gut development and function.

SKIV2L mutations cause syndromic diarrhea, or trichohepatoenteric syndrome.

Syndromic diarrhea (or trichohepatoenteric syndrome) is a rare congenital bowel disorder characterized by intractable diarrhea and woolly hair, and it has recently been associated with mutations in TTC37. Although databases report TTC37 as being the human ortholog of Ski3p, one of the yeast Ski-complex cofactors, this lead was not investigated in initial studies. The Ski complex is a multiprotein complex required for exosome-mediated RNA surveillance, including the regulation of normal mRNA and the decay of nonfunctional mRNA. Considering the fact that TTC37 is homologous to Ski3p, we explored a gene encoding another Ski-complex cofactor, SKIV2L, in six individuals presenting with typical syndromic diarrhea without variation in TTC37. We identified mutations in all six individuals. Our results show that mutations in genes encoding cofactors of the human Ski complex cause syndromic diarrhea, establishing a link between defects of the human exosome complex and a Mendelian disease.

Ara h 2 and Ara h 6 sensitization predicts peanut allergy in Mediterranean pediatric patients.

BACKGROUND: Peanut allergy (PA) management was improved by the introduction of molecular allergology, but guidelines for Mediterranean patients are lacking. We aimed at evaluating peanut component-resolved diagnosis as a diagnostic and prognostic tool in children from Southern France. METHODS: In 181 pediatric patients, PA diagnosis was founded on medical history, skin prick testing, serum-specific IgE to Arachis hypogea extract and components, Pru p 4, and plant carbohydrates, and oral food challenge. Allergen microarray was also performed in 68 of these patients. RESULTS: In peanut-allergic children (n = 117), IgE to Ara h 6 were most prevalent (64%), followed by Ara h 2 (63%), Ara h 1 (60%), and Ara h 9 (52%). Ara h 6 was the best predictor of PA. The second best predictor was the ratio of Ara h 2 IgE to peanut IgE (cutoff 0.113). Persistent childhood PA was associated with complex molecular profiles. Comparison of singleplex and microarray results showed poor concordance for Ara h 2 and Ara h 9. CONCLUSION: Ara h 6 and Ara h 2 are the best predictors of PA at diagnosis in Mediterranean pediatric patients. Ara h 1, Ara h 8, and molecular complexity are associated with PA persistence.

Heterogeneity of follow-up procedures in French and Belgian patients with treated hereditary tyrosinemia type 1: results of a questionnaire and proposed guidelines.

The 1991 introduction of 2-(2-nitro-4-trifluoro-methylbenzyol)-1,3 cyclohexanedione (NTBC) as a treatment for hereditary tyrosinemia type 1 (HT-1), a disorder of tyrosine catabolism, has radically modified the natural history of this disorder. Despite the dramatic improvements in survival, outcomes and quality of life seen with NTBC treatment, HT-1 remains a chronic disorder with several long-term complications, including, a persistent (albeit low) risk of hepatocellular carcinoma and suboptimal neuropsychological outcomes. There remain unsolved key-questions concerning the long-term outcomes of patients with HT-1, which closely depend on the quality of follow-up in these patients. In the absence of published guidelines, we investigated the follow-up methods used for French and Belgian patients with HT-1. A simple questionnaire providing a rapid overview of follow-up procedures was sent to the 19 physicians in charge of HT-1 patients treated with NTBC and low-tyrosine diet in France and Belgium. Several areas of heterogeneity (especially liver imaging, slit lamp examination, neuropsychological evaluation and maximal plasma tyrosine level accepted) were observed. In an attempt to improve long-term management and outcome of patients with HT-1, we proposed follow-up recommendations.

Severity scores in children with acute pancreatitis.

Severity scores are used to predict the outcome of acute pancreatitis (AP). Several scores are used in adult patients, but none has been thoroughly validated for specific use in paediatric patients. We retrospectively collected data from 48 children with AP (13 severe and 35 mild). The main causes were trauma (23%), idiopathic (23%), lithiasis (12.5%), and virus (10.5%). We evaluated 3 clinical scores (Ranson, Glasgow modified, and DeBanto) and Balthazar computed tomography severity index. The clinical scores had a good specificity (approximately 85%) but a low sensitivity (approximately 55%) in predicting the severity of paediatric AP. The radiological score is better (sensitivity 80%, specificity 86%). The area under the receiver operator characteristic curve was 0.699 (95% CI 0.508%-0.891%, P = 0.054) for the DeBanto score, 0.846 (95% CI 0.69%-1%, P = 0.001) for the Ranson score, and 0.774 (95% CI 0.584%-0.964%, P = 0.008) for the Glasgow and 0.898 (95% CI 0.73%-1%, P = 0.011) for the Balthazar computed tomography severity index score. In our paediatric cohort, the severity of AP was best predicted by Balthazar computed tomography-based scoring scale. Our results confirm previously reported low sensitivity of adult-based clinical scoring scales.

Novel mutations in TTC37 associated with tricho-hepato-enteric syndrome.

The Tricho-Hepato-Enteric (THE) syndrome is an autosomal recessive condition marked by early and intractable diarrhea, hair abnormalities, and immune defects. Mutations in TTC37, which encodes the putative protein Thespin, have recently been associated with THE syndrome. In this article, we extend the pattern of TTC37 mutations by the description of 11 novel mutations in 9 patients with a typical THE syndrome. The mutations were spread along the gene sequence, none of themrecurrent. Different types of mutation were observed: frameshift mutations, splice-site altering mutations, or missense mutations, most of them leading to the creation of a premature stop codon. Concurrently, we investigated the pattern of TTC37 expression in a panel of normal human tissues and showed that this gene is widely expressed, with high levels in vascular tissues, lymph node, pituitary, lung, and intestine. In contrast, TTC37 is not expressed in the liver, an organ that is not consistently affected in THE syndrome. Last, we suggested a model for the putative structure of the unknown Thespin protein.

Clinical phenotype and genotype of children with borderline sweat test and abnormal nasal epithelial chloride transport.

RATIONALE: The diagnosis of cystic fibrosis (CF) is based on a characteristic clinical picture in association with a sweat chloride (Cl(-)) concentration greater than 60 mmol/L or the identification of two CF-causing mutations. A challenging problem is the significant number of children for whom no definitive diagnosis is possible because they present with symptoms suggestive of CF, a sweat chloride level in the intermediate range between 30 and 60 mmol/L, and only one or no identified CF-causing mutation. OBJECTIVES: To investigate the function of the cystic fibrosis transmembrane conductance regulator (CFTR) protein in the airways of children with intermediate sweat tests and inconclusive genetic findings in correlation with clinical phenotype and genotype. METHODS: We developed a composite nasal potential difference (NPD) diagnostic score to discriminate patients with CF from non-CF patients. We tested NPD in 50 children (age, 6 mo to 18 yr) with equivocal diagnoses and correlated the NPD diagnostic score with clinical phenotypes and genotypes. MEASUREMENTS AND MAIN RESULTS: Fifteen of the 50 children had NPD scores in the CF range. Eight of the 15 carried two CFTR mutations compared with only 5 of the 35 children with normal NPD scores (P = 0.01). They were significantly younger at evaluation and had recurrent lower respiratory tract infections, chronic productive coughs, and chronic Staphylococcus aureus colonization significantly more often than the 35 children with normal NPD results. CONCLUSIONS: Evaluation of CFTR function in the nasal epithelium of children with inconclusive CF diagnoses can be a useful diagnostic tool and help clinicians to individualize therapeutic strategy.

Outbreak of Corynebacterium pseudodiphtheriticum infection in cystic fibrosis patients, France.

An increasing body of evidence indicates that nondiphtheria corynebacteria may be responsible for respiratory tract infections. We report an outbreak of Corynebacterium pseudodiphtheriticum infection in children with cystic fibrosis (CF). To identify 18 C. pseudodiphtheriticum strains isolated from 13 French children with CF, we used molecular methods (partial rpoB gene sequencing) and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. Clinical symptoms were exhibited by 10 children (76.9%), including cough, rhinitis, and lung exacerbations. The results of MALDI-TOF identification matched perfectly with those obtained from molecular identification. Retrospective analysis of sputum specimens by using specific real-time PCR showed that approximately 20% of children with CF were colonized with these bacteria, whereas children who did not have CF had negative test results. Our study reemphasizes the conclusion that correctly identifying bacteria at the species level facilitates detection of an outbreak of new or emerging infections in humans.

Exclusion of EGFR, HRAS, DSP, JUP, CTNNB1, PLEC1, and EPPK1 as functional candidate genes in 7 families with syndromic diarrhoea.

Syndromic diarrhoea (SD) is a rare disease associating intractable diarrhoea and hair abnormalities. In an attempt to identify the gene causative for SD, we studied several functional candidate genes, based on their implication in overlapping phenotypes in mice (EGFR) or in humans (HRAS, JUP, DSP EPPK1, PLEC1, and CTNNB1) in 8 patients affected by SD. Except for EGFR and HRAS, all selected genes encode for cell adhesion proteins. Using direct sequencing or linkage analysis, we excluded all of the candidate genes as the disease-causing gene in our group of patients; however, the hypothesis of intercellular junctions defect in SD remains seductive.

Incidence of autoimmune diseases in celiac disease: protective effect of the gluten-free diet.

BACKGROUND & AIMS: Celiac disease may be associated with autoimmune diseases. The aims of the present study were to determine in celiac patients which factors modulate the risk of autoimmune disease and to evaluate the effect of the gluten-free diet. METHODS: The occurrence of autoimmune disease and compliance to gluten-free diet were specified retrospectively in 924 celiac patients recruited from 27 French pediatric and adult gastroenterology centers. RESULTS: One or several autoimmune diseases had developed in 178 patients. The cumulative risk of autoimmune disease was 8.1% +/- 1% at age 15, and 15.7% +/- 1.5% at age 30. Factors associated with an increased risk were family history of autoimmunity (hazard ratio, 2.36; 95% confidence interval, 1.71-3.31) and diagnosis of celiac disease before 36 years of age (hazard ratio, 2.65; 95% confidence interval, 1.79-3.85). After diagnosis of celiac disease, 55 of 788 patients developed an autoimmune disease. The cumulative risk of subsequent autoimmune disease was lower in patients compliant to a gluten-free diet versus noncompliant patients (at 10 years, 6% +/- 2% vs 15.6% +/- 5.9%, respectively; P = .02). The incidence of autoimmune diseases was 5.4 per 1000 patient-years during adherence to a gluten-free diet versus 11.3 per 1000 patient-years during nonadherence to the diet (P = .002). Results were similar in both the pediatric and the adult populations. CONCLUSIONS: Celiac patients most at risk for autoimmune disease are those diagnosed early in life and having a family history of autoimmunity. The gluten-free diet has a protective effect.

Liver disease associated with ZZ alpha1-antitrypsin deficiency and ursodeoxycholic acid therapy in children.

OBJECTIVES: To investigate the effect of ursodeoxycholic acid (UDCA) in children with liver disease associated with ZZ alpha1-antitrypsin (AAT) deficiency. PATIENTS AND METHODS: A total of 42 affected children received UDCA (30 mg x kg x day(-1)) and underwent clinical and biochemical follow-up at least yearly. RESULTS: In group 1, 22 children whose mean initial gamma-glutamyl-transpeptidase (GGT) was 7.4 x N normalized serum liver test results after a mean treatment of 2.6 years. In 16 of these children, UDCA was discontinued. Relapse was observed in 11 children, and liver test results returned to normal after UDCA resumption. In the other 5 children, liver test results remained normal during a mean period of 2.5 years. In group 2, 11 children (mean initial GGT 12.8 x N) had improved liver test results after a mean treatment of 2.3 years. In group 3, 9 children (mean initial GGT 33.8 x N) had no liver test result improvement and evolution toward cirrhosis, requiring liver transplantation in 7. Most of the children in group 1 had normal results of clinical examination after UDCA treatment, versus none in group 3 (P < or = 0.00001). Initial GGT (P < or = 0.002) and total bilirubin (P < or = 0.05) levels were significantly lower in group 1 than in group 3. Combined initial values of GGT < or =5.5 x N and total bilirubin < or =66 micromol/L were associated with normalization of liver test results in 90% of children. CONCLUSIONS: UDCA may significantly improve clinical status and liver test results in some children with liver disease associated with ZZ AAT deficiency. No beneficial effect of UDCA was shown in children with the most severe liver involvement. Initial levels of GGT and total bilirubin may be of prognostic value for therapy effectiveness.

[Mycophenolate mofetil restores renal function and spares steroids during idiopathic nephrotic syndrome in children. A cohort study]. / Le mycophénolate mofétil améliore la fonction rénale et l'imprégnation cortisonique au cours du syndrome néphrotique corticodépendant de l'enfant. Une étude de cohorte.

Renal function evolution during idiopathic nephrotic syndrome depends on treatment toxicity. Cyclosporin is effective as a steroid-sparing agent but patients are dependant on this drug, which can lead to renal toxicity. Mycophenolate mofetil, a widely used drug in organ transplantation, has short-term beneficial effects in glomerular diseases, including idiopathic nephrotic syndrome. Little is known about mycophenolate mofetil in children and long-term evolution. We analysed a cohort of 12 children with steroid-dependant nephrotic syndrome due to minimal change disease in remission with cyclosporine therapy. They were switched to mycophenolate mofetil, when renal toxicity was diagnosed. We evaluated the number of relapses, tolerance of this new treatment, renal function and body mass index under mycophenolate. After a follow-up of 31.25 months, mycophenolate mofetil alone was effective in preventing relapses in eight patients, without side effects. Renal function significantly improved and the final body mass index decreased. Three patients relapsed on discontinuation of mycophenolate mofetil. The results suggest that mycophenolate mofetil is effective and safe in preventing relapses in steroid-dependant nephrotic syndrome. Furthermore, switching from cyclosporine to mycophenolate mofetil restores renal function. Therefore, mycophenolate mofetil might be considered as an alternative to cyclosporine, to preserve renal function and spare steroids during idiopathic nephrotic syndrome in children.

Nebulisers comparison with inhaled tobramycin in young children with cystic fibrosis.

BACKGROUND: This randomised cross-over pilot study was undertaken in 10 cystic fibrosis children aged 10 to 63 months to describe lung absorption of tobramycin delivered by the PariLC+/PariTurboboyN (Pari GmbH) and the disposable NL9M/AtomisorBoxPlus (Diffusion Technique Française) nebulising systems. METHODS: Each child inhaled 300 mg tobramycin delivered with one or the other apparatus via a facemask in two separate and standardised sessions. Urine was collected for 6 h. Tobramycin concentrations determined by immunoprecipitation were expressed in mg per g of creatinine and compared by a Wilcoxon test for matched pairs. The influences of age, weight and Brasfield score on this parameter were evaluated by correlation tests, and those of sex, previous nebulisation treatment, and crying or coughing were evaluated by Student's t-test. RESULTS: The amount of tobramycin measured in urines was low and variable. Median values for urinary tobramycin concentration were 47.6 mg/g (14.9-79.6) with the PariLC+ and 42.6 mg/g (6.3-112.8) with the NL9M (p=0.6). PariLC+ delivered tobramycin in 22 min and NL9M in 12 min (p=0.005). Crying or coughing dramatically reduced the amount of tobramycin collected. CONCLUSION: This pilot study shows that evaluation of nebulisers based on tobramycin renal excretion is feasible in young children with cystic fibrosis.

A familial form of congenital hypopituitarism due to a PROP1 mutation in a large kindred: phenotypic and in vitro functional studies.

We report the natural history of a hypopituitarism in a large Tunisian kindred including 29 subjects from the same consanguineous family. The index case was a 9-yr-old girl with severe growth retardation due to complete GH deficiency and partial corticotroph, lactotroph, and thyrotroph deficiencies. Magnetic resonance imaging showed a hyperplastic anterior pituitary. Thirteen of the 28 relatives examined (10 female subjects) had hypopituitarism. In the 14 patients, previously untreated (aged 6-53 yr), height was -5.7 +/- 1.7 sd score, and puberty was spontaneously initiated in only two females. Complete GH deficiency was found in all 12 patients investigated, of whom 11 had thyrotroph and eight of 10 had corticotroph deficiency. A homozygous R73C mutation of PROP1 was present in all 10 patients studied, and a heterozygous mutation was found in six unaffected parents or siblings. In vitro the mutant had 11.5% of the transactivation capacity of the wild type and was unable to bind to a high-affinity DNA sequence. This report showed the deleterious effect of the recessive R73C mutation that affects a hot spot of the PROP1 gene and was associated with severe dwarfism, a lack of spontaneous puberty, and a high incidence of early onset of corticotroph deficiency.

Efficacy and tolerance of infliximab in children and adolescents with Crohn's disease.

Infliximab, a monoclonal antibody against tumor necrosis factor-alpha, has been shown to be effective for the treatment of refractory Crohn's disease in adult patients, but experience in pediatrics is limited. This retrospective study included 88 children and adolescents, 39 girls and 49 boys, with a median age of 14 years (range 3.3-17.9). Infliximab was indicated for active disease (66%) and/or fistulas (42%) that were refractory to corticosteroids (70%), and/or other immunosuppressive (82%) agents, and/or parenteral nutrition (20%). Patients received 1 to 17 infusions (median 4) of 5 mg/kg (range 3.8-7.3) of infliximab during a median time period of 4 months (1-17 months). Infusion reaction was noted in 13 patients (15%), with a total of 16 reactions in 450 infusions (4%). At Day 90 after the first infusion of infliximab, symptoms improved in 49% of patients, whereas 29% of patients were in remission and 13% of patients relapsed. From Day 0 to Day 90, Harvey-Bradshaw score decreased from 7.5 to 2.8 (P < 0.001), C-reactive protein from 36 to 16 mg/L (P < 0.01), and 1-hour erythrocyte sedimentation rate from 35 to 17 mm (P < 0.01). Dosage of corticosteroids decreased from to 0.59 to 0.17 mg/kg/d (P < 0.001); 53% of patients could be weaned of corticosteroids and 92% of parenteral nutrition. Treatment with infliximab is well tolerated and effective in most children and adolescents with Crohn's disease that is refractory to conventional immunosuppressive therapy. Nevertheless, long-term efficacy remains to be shown, and further studies are urgently needed to precisely determine the best modality of continuing treatment.

High heterogeneity of CFTR mutations and unexpected low incidence of cystic fibrosis in the Mediterranean France.

In this report, we present updated spectrum and frequency of mutations of the CFTR gene that are responsible for cystic fibrosis (CF) in Languedoc-Roussillon (L-R), the southwestern part of France. A total of 75 different mutations were identified by DGGE in 215 families, accounting for 97.6% of CF genes and generating 88 different mutational genotypes. The frequency of p.F508del was 60.23% in L-R versus 67.18% in the whole country and only five other mutations (p.G542X, p.N1303K, p.R334W, c.1717-1G>A, c.711+1G>T) had a frequency higher than 1%. The mutations were scattered over 20 exons or their border. This sample representing only 5.7% of French CF patients contributed to 24% of CFTR mutations reported in France. This is one of the highest molecular allelic heterogeneity reported so far in CF. We also present the result of a neonatal screening program based on a two-tiered approach "IRT/20 mutations/IRT" analysis on blood spots, implemented in France with the aim to improve survival and quality of life of patients diagnosed before clinical onset. This 18-month pilot project showed an unexpected low incidence of CF (1/8885) in South of France, with only six CF children detected among 43,489 neonates born in L-R, and 13 among 125,339 neonates born in Provence-Alpes-Côte-d'Azur (PACA).

Neonatal screening for cystic fibrosis: comparing the performances of IRT/DNA and IRT/PAP.

BACKGROUND: French health authorities promoted a study on 553,167 newborns comparing the performances of IRT/DNA and IRT/PAP for CF newborn screening. METHODS: In parallel to IRT/DNA, PAP was assayed in newborns with IRT>50 µg/L. Provisional PAP cutoffs at 3.0 µg/L when 50100 were used. Positive newborns were subjected to sweat test. Optimal cutoffs were established by a non-inferiority method. RESULTS: 95 CF newborns were identified (83 classical forms (ClF), including 9 meconium ileus (MI), and 12 atypical (mild) forms (AF) Of them, IRT/DNA identified 85 (73 ClF including 5 MI and 12 AF). PAP cutoffs at 1.8 µg/L when 50< IRT<100 µg/L and 0.6 µg/L when IRT>100 µg/L would identify 82 CF: 77 ClF, including 8 MI, and 5 AF. The number of sweat tests was 314 and 1039 in the IRT/DNA and IRT/PAP strategies, respectively. CONCLUSIONS: Using the optimal cutoffs, the sensitivity of the IRT/PAP strategy would not be inferior to that of IRT/DNA if identification of MF is not required.

Syndromic (phenotypic) diarrhoea of infancy/tricho-hepato-enteric syndrome.

OBJECTIVES: Syndromic diarrhoea/tricho-hepato-enteric syndrome (SD/THE) is a rare congenital syndrome. The main features are intractable diarrhoea of infancy, hair abnormalities, facial dysmorphism, intrauterine growth restriction and immune system abnormalities. It has been linked to abnormalities in two components of the putative human ski complex: SKIV2L and TTC37. The long-term outcome of this syndrome is still unknown. We aim to describe the long-term outcome, in the French cohort of patients born since 1992. DESIGN: Review of the clinical and biological features of the 15 patients with SD/THE, followed in France and born between 1992 and 2010. RESULTS: All patients presented typical SD/THE syndrome features, of intractable diarrhoea in infancy requiring parenteral nutrition, a facial dysmorphism with hair abnormalities, and immunological disorders. Half of them also had liver and skin abnormalities. Five children died, among which 3 died due to infections. Probabilities of survival according to the Kaplan-Meier method were 93.3%, 86.7%, 74.3 and 61.9%, respectively at 1 year, 5 years, 10 years and 15 years of age. 3/15 were weaned from parenteral nutrition (PN) with likelihood of weaning being 10% at 5 years and 40% at 10 years. At birth 80% were small for gestational age and the short stature persisted in 60%. Haemophagocytic syndrome was noted in 60% and mild mental retardation was present in 60%. CONCLUSIONS: SD/THE is a rare disease with high morbidity and mortality. Management should be focused on nutrition and immunological defects.