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

Genotype-phenotype spectrum and prognosis of early-onset Marfan syndrome /

Background Marfan syndrome is a genetic connective tissue disorder affecting skeletal, ocular, and cardiovascular organ systems. Previous research found that pathogenic variants clustered in exons 24–32 of fibrillin-1 (FBN1) gene result in more severe clinical phenotypes. Furthermore, genotype-phenotype correlation studies suggested that more severe cardiovascular phenotypes were related to variants held responsible for haploinsufficiency. Our objective was to analyze the differences in clinical manifestations and genotypes of individuals with early-onset Marfan syndrome and to assess their impact on management strategies. Methods We analyzed clinical and genetic data of a new patient with early-onset Marfan syndrome together with 51 previously reported ones in the PubMed database between 1991 and 2022. Results Analysis showed 94% (49/52) of pathogenic variants clustered in exons 24–32 of the FBN1. The most common skeletal features were arachnodactyly (98%), reduced elbow extension (48%), pectus deformity (40%), and scoliosis (39%). Haploinsufficiency variants were reported as having poor outcome in 87.5% of the cases. Among patients carrying variants that substitute a cysteine for another amino acid and those that do not change cysteine content, cardiac intervention was found to be associated with a better outcome (p=0.035 vs. p=0.002). Variants that create an extra cysteine residue were found to be associated with a higher risk of ectopia lentis. Additionally, children up to 36-months-old were more often reported as still alive at the time of publication compared to newborns (p<0.01). Conclusions Our findings have implications for prognosis, because different genotype groups and their resulting phenotype may require personalized care and management

Wide diagnostic and genotypic spectrum in patients with suspected mitochondrial disease /

Background Mitochondrial Diseases (MDs) are a diverse group of neurometabolic disorders characterized by impaired mitochondrial oxidative phosphorylation and caused by pathogenic variants in more than 400 genes. The implementation of next-generation sequencing (NGS) technologies helps to increase the understanding of molecular basis and diagnostic yield of these conditions. The purpose of the study was to investigate diagnostic and genotypic spectrum in patients with suspected MD. The comprehensive analysis of mtDNA variants using Sanger sequencing was performed in the group of 83 unrelated individuals with clinically suspected mitochondrial disease. Additionally, targeted next generation sequencing or whole exome sequencing (WES) was performed for 30 patients of the study group. Results The overall diagnostic rate was 21.7% for the patients with suspected MD, increasing to 36.7% in the group of patients where NGS methods were applied. Mitochondrial disease was confirmed in 11 patients (13.3%), including few classical mitochondrial syndromes (MELAS, MERRF, Leigh and Kearns-Sayre syndrome) caused by pathogenic mtDNA variants (8.4%) and MDs caused by pathogenic variants in five nDNA genes. Other neuromuscular diseases caused by pathogenic variants in seven nDNA genes, were confirmed in seven patients (23.3%). Conclusion The wide spectrum of identified rare mitochondrial or neurodevelopmental diseases proves that MD suspected patients would mostly benefit from an extensive genetic profiling allowing rapid diagnostics and improving the care of these patients

Early bilateral gonadoblastoma in a patient with mixed gonadal dysgenesis (karyotype 45,X/46,XY): case report and review of literature

Background: Mixed gonadal dysgenesis is a rare congenital and challenging condition, characterized mainly by 45,X/46,XY karyotype mosaicism, asymmetrical gonadal development and various internal and external genital anatomy. Because of frequent disorder of genital development and a higher risk of germ cell neoplasia, management of these patients is complex and requires multidisciplinary approach. Case: We present a 45,X/46,XY mixed gonadal dysgenesis patient diagnosed with gonadoblastoma in both gonads after bilateral gonadectomy at 1 year of age. Conclusions: Because of high risk for malignant transformation, gonadectomy of a streak-like gonad and biopsy with orchidopexy or gonadectomy of a dysgenetic testicle is recommended at an early age

Reverse phenotyping maternal cystic kidney disease by diagnosis in a newborn: case report and literature review on neonatal cystic kidney diseases

Kidney cysts are the most common kidney lesion, while congenital kidney cysts are mostly found in pediatric population. Neonatal kidney cysts can develop due to fetal malformations, rare genetic disorders or can be acquired which is very rare. Kidney cysts may be the only isolated finding or be part of the overall phenotype. They can be asymptomatic, found by ultrasound accidentally or can manifest from mild to life-threatening symptoms. Therefore, early diagnosis is very important. Autosomal dominant polycystic kidney disease and autosomal recessive polycystic kidney disease are the most common causes of kidney cysts in the neonatal population. This review highlights the most common kidney cystic diseases during the neonatal period and a rare clinical case of HNF1B-associated disease

Kearns-Sayre syndrome case. Novel 5,9 kb mtDNA deletion

Background: Kearns- Sayre syndrome (KSS) is a rare multisystem mitochondrial disorder characterized by onset before 20 years of age and a typical clinical triad: progressive external ophthalmoplegia, pigmentary retinopathy and cardiac con-duction anomalies. In most cases KSS is caused by spontaneous heteroplasmic single large- scale mitochondrial DNA (mtDNA) deletions. Long- range polymer-ase chain reaction (LR- PCR), next generation sequencing (NGS) and multiplex ligation- dependent probe amplification (MLPA) are the most widely applied methods for the identification of mtDNA deletions. Here, we report the case of 20- year- old male who presented with classic Kearns- Sayre syndrome, confirmed by novel 5,9 kb mtDNA deletion.Methods and results: LR- PCR and MLPA methods were applied to identify the mitochondrial DNA deletion for the patient, but the results were conflict-ing. Molecular analysis using primer walking and Sanger sequencing identified a novel 5888 base pairs mtDNA deletion (NC_012920.1:m.6069_11956del) with CAAC nucleotides repeat sequence at the breakpoints.Conclusion: Our study enriched the mtDNA variation spectrum associated with KSS and demonstrated the importance of choosing relevant molecular genetic methods