Genotype-phenotype relationships of truncating mutations, p.E297G and p.D482G in bile salt export pump deficiency

Background & Aims: Bile salt export pump (BSEP) deficiency frequently necessitates liver transplantation in childhood. Homozygous p.D482G or p.E297G mutations are associated with relatively mild phenotypes, responsive to surgical interruption of the enterohepatic circulation (siEHC), in contrast to patients with two predicted protein truncating mutations (PPTM). The phenotype of patients with a compound heterozygous genotype of one p.D482G or p.E297G mutation and one PPTM has remained unclear. We aimed to assess their genotype-phenotype relationship. Methods: From the NAPPED database, we selected patients with homozygous p.D482G or p.E297G mutations (BSEP1/1; n=31), with one p.D482G or p.E297G, and one PPTM (BSEP1/3; n=30), and with two PPTMs (BSEP3/3; n=77). We compared presentation, native liver survival (NLS), and effect of siEHC on NLS. Results: The groups had a similar median age at presentation (0.7-1.3 years). Overall NLS at age 10 years was 21% in BSEP1/3 vs. 75% in BSEP1/1 and 23% in BSEP3/3 (P<0.001). Without siEHC in their follow-up, NLS of BSEP1/3 was similar to BSEP3/3 patients, but considerably lower than BSEP1/1 patients (at age 10 years: 38%, 30%, and 71%, resp; P=0.003). After siEHC, BSEP1/3 and BSEP3/3 patients had similarly low NLS, while this was much higher in BSEP1/1 patients (10 years after siEHC, 27%, 14%, and 92%, resp.; P<0.001). Conclusions: BSEP deficiency patients with one p.E297G or p.D482G mutation and one PPTM have a similarly severe disease course and low responsiveness to siEHC as patients with two PPTMs. This identifies a considerable subgroup of patients who are unlikely to benefit from interruption of the enterohepatic circulation by either surgical or ileal bile acid transporter inhibitor treatment

Genetic landscape of pediatric acute liver failure of indeterminate origin.

BACKGROUND AIMS Pediatric acute liver failure (PALF) is a life-threatening condition. In Europe, main causes are viral infections (12-16%) and inherited metabolic diseases (14-28%). Yet, in up to 50% of cases the underlying etiology remains elusive, challenging clinical management, including liver transplantation. We systematically studied indeterminate PALF cases referred for genetic evaluation by whole-exome sequencing (WES), and analyzed phenotypic and biochemical markers, and the diagnostic yield of WES in this condition. METHODS With this international, multicenter observational study, patients (0-18 y) with indeterminate PALF were analyzed by WES. Data on the clinical and biochemical phenotype were retrieved and systematically analyzed. RESULTS In total, 260 indeterminate PALF patients from 19 countries were recruited between 2011 and 2022, of whom 59 had recurrent PALF (RALF). WES established a genetic diagnosis in 37% of cases (97/260). Diagnostic yield was highest in children with PALF in the first year of life (46%), and in children with RALF (64%). Thirty-six distinct disease genes were identified. Defects in NBAS (n=20), MPV17 (n=8) and DGUOK (n=7) were the most frequent findings. When categorizing, most frequent were mitochondrial diseases (45%), disorders of vesicular trafficking (28%) and cytosolic aminoacyl-tRNA synthetase deficiencies (10%). One-third of patients had a fatal outcome. Fifty-six patients received liver transplants. CONCLUSION This study elucidates a large contribution of genetic causes in PALF of indeterminate origin with an increasing spectrum of disease entities. The high proportion of diagnosed cases and potential treatment implications argue for exome or in future rapid genome sequencing in PALF diagnostics

Autoregressive cross-lagged models of IMPACT-III and Pediatric Crohn's Disease Activity Indexes during one year infliximab therapy in pediatric patients with Crohn's disease.

BACKGROUND Quality of life (QoL) is an important outcome measure in the evaluation of therapies for inflammatory bowel disease. The primary aim of this study was to determine the effect of one year infliximab treatment on QoL and clinical parameters in pediatric patients with Crohn's diseases (CD). METHODS Our prospective study involved 51 children with conventional therapy resistant, severe CD (mean age: 15.25years, range: 11-18years). Infliximab was given according to the protocol (5mg/kg, at weeks 0, 2, 6 and every 8weeks). During the infliximab courses QoL of patients was evaluated by IMPACT-III questionnaire at weeks 0, 6, 30 and 53. At the same time, the Pediatric Crohn's Disease Activity Index (PCDAI) score was calculated. Moreover, serum C-reactive protein (CRP), serum platelets and serum albumin were followed up. Auto-regressive, cross-lagged models were used to assess relation between QoL and the clinical parameters. RESULTS The initial IMPACT-III scores [median, percentile 25-75 (pc 25-75) at week 0: 115, 102.5-130.25] increased significantly (p<0.001) following infliximab therapy at week 54 (median: 141.5, 124.5-153.75). Clinical and laboratory parameters also improved significantly (p<0.001). Auto-regressive regression coefficients (β value) were significant between each variable over time. The strongest cross-lagged relations were observed between IMPACT-III and serum albumin, IMPACT-III and platelets. Reliability test of IMPACT-III revealed an excellent level of internal consistency (Cronbach's alpha=0.931). CONCLUSION Infliximab treatment has beneficial clinical effect which is confirmed by decrease of PCDAI and increase of IMPACT-III. Autoregressive regression analysis showed regression relation between IMPACT-III and PCDAI and laboratory parameters

Crohn-beteg gyermekek infliximabkezelésének kezdeti tapasztalatai hazánkban [Analysis of infliximab treated pediatric patients with Crohn disease in Hungary]

Infliximab, the chimeric antibody to tumor necrosis factor-alpha, is indicated for medically refractory pediatric Crohn disease. Aim of our study was to examine the efficacy and side effects of infliximab therapy in Hungarian pediatric patients with Crohn disease since the authorisation of medicine for children to 31.12.2008. 23 children with refractory Crohn disease received infliximab during this period. Induction therapy with 5 mg/kg infliximab at weeks 0, 2, and 6 was introduced. 18 patients (81.8%) achieved clinical response, and 13 patients (59.1%) were in remission at the 6th week of the observation period. The evaluation was based on data of 22 children. Fistula closure rate was 70% at the at the 6th week. Two patients had acute infusion reaction, one had severe anaphilactic reaction after infliximab infusion. Chronic side effects were also observed in three cases. In our study infliximab induction therapy was effective in most pediatric patients with therapy refractory Crohn disease

Outcome of infants diagnosed with 3-methyl-crotonyl-CoA-carboxylase deficiency by newborn screening

Introduction: 3-Methyl CoA carboxylase (3-MCC) deficiency is an inborn error of metabolism in the catabolism of the amino acid leucine. Original reports suggested this disorder was associated with significant neurological and biochemical effects. However newborn screening has identified a higher than expected incidence of this disorder with apparent normal outcome in most cases. Method: A retrospective analysis of thirty-five cases of 3-MCC deficiency identified by newborn screening and diagnosed by enzyme or molecular analysis. Results: There was a strong inverse correlation between initial C5OH level and residual enzyme activity. A few reports of hypoglycemia, ketosis, poor feeding/failure to thrive or fasting intolerance were reported, but there was no clear relationship between symptoms and residual enzyme activity. Developmental outcome included several children with mental retardation (including one with Down syndrome and one with schizencephaly) and two with Autism Spectrum disorders but there was no apparent relationship to residual enzyme activity. Free carnitine deficiency was relatively common. Discussion: Although residual enzyme activity was clearly related to metabolite elevation, there was no apparent relationship with other measures of outcome. The number of reports of neurologic abnormalities or metabolic symptoms (poor feeding, hypoglycemia, fasting intolerance, etc.) is concerning, but the significance is unclear in this retrospective sample. © 2012 Elsevier Inc

Event-free survival of maralixibat-treated patients with Alagille syndrome compared to a real-world cohort from GALA

BACKGROUND AND AIMS: Alagille syndrome (ALGS) is characterized by chronic cholestasis with associated pruritus and extrahepatic anomalies. Maralixibat, an ileal bile acid transporter inhibitor, is an approved pharmacologic therapy for cholestatic pruritus in ALGS. Since long-term placebo-controlled studies are not feasible or ethical in children with rare diseases, a novel approach was taken comparing 6-year outcomes from maralixibat trials with an aligned and harmonized natural history cohort from the G lobal AL agille A lliance (GALA) study.APPROACH AND RESULTS: Maralixibat trials comprise 84 patients with ALGS with up to 6 years of treatment. GALA contains retrospective data from 1438 participants. GALA was filtered to align with key maralixibat eligibility criteria, yielding 469 participants. Serum bile acids could not be included in the GALA filtering criteria as these are not routinely performed in clinical practice. Index time was determined through maximum likelihood estimation in an effort to align the disease severity between the two cohorts with the initiation of maralixibat. Event-free survival, defined as the time to first event of manifestations of portal hypertension (variceal bleeding, ascites requiring therapy), surgical biliary diversion, liver transplant, or death, was analyzed by Cox proportional hazards methods. Sensitivity analyses and adjustments for covariates were applied. Age, total bilirubin, gamma-glutamyl transferase, and alanine aminotransferase were balanced between groups with no statistical differences. Event-free survival in the maralixibat cohort was significantly better than the GALA cohort (HR, 0.305; 95% CI, 0.189-0.491; p &lt;0.0001). Multiple sensitivity and subgroup analyses (including serum bile acid availability) showed similar findings.CONCLUSIONS: This study demonstrates a novel application of a robust statistical method to evaluate outcomes in long-term intervention studies where placebo comparisons are not feasible, providing wide application for rare diseases. This comparison with real-world natural history data suggests that maralixibat improves event-free survival in patients with ALGS.</p

Incidence, Paris classification, and follow-up in a nationwide incident cohort of pediatric patients with inflammatory bowel disease.

OBJECTIVES The aim of the study was to evaluate the incidence, baseline disease characteristics, and disease location based on the Paris classification in pediatric inflammatory bowel disease (IBD) in the Hungarian nationwide inception cohort. In addition, 1-year follow-up with therapy was analyzed. METHODS From January 1, 2007 to December 31, 2009, newly diagnosed pediatric patients with IBD were prospectively registered. Twenty-seven pediatric gastroenterology centers participated in the data collection ensuring the data from the whole country. Newly diagnosed patients with IBD younger than 18 years were reported. Disease location was classified according to the Paris classification. RESULTS A total of 420 patients were identified. The incidence rate of pediatric IBD was 7.48/10⁵ (95% confidence interval [CI] 6.34/10⁵-8.83/10⁵). The incidence for Crohn disease (CD) was 4.72/10⁵ (95% CI 3.82-5.79), for ulcerative colitis (UC) 2.32/10⁵ (95% CI 1.71-3.09), and for IBD-unclassified 0.45/10⁵ (95% CI 0.22-0.84). Most common location in CD was L3 (58.7%); typical upper gastrointestinal abnormalities (ulcer, erosion and aphthous lesion) were observed in 29.9%. Extensive colitis in patients with UC (E4, proximal to hepatic flexure) was the most common disease phenotype (57%), whereas only 5% of children had proctitis. A total of 18.6% of patients had ever severe disease (S1). Frequency of azathioprine administration at diagnosis was 29.5% in patients with CD, and this rate increased to 54.6% (130/238) at 1-year follow-up. In UC, only 3.3% received azathioprine initially, and this rate elevated to 22.5% (25/111). Use of corticosteroid decreased from 50% to 15.3% in patients with UC. Rate of bowel resection in patients with CD during the first year of follow-up was 5%. CONCLUSIONS The incidence of pediatric IBD in Hungary was among the higher range reported. This is the first large, nationwide incident cohort analyzed according to the Paris classification, which is a useful tool to determine the characteristic pediatric CD phenotype