Enteric anendocrinosis attributable to a novel Neurogenin-3 variant

Investigating the genetic profile of familial atypical cystic fibrosis patients (DeltaF508-CFTR) with neonatal biliary atresia

Biliary atresia (BA) is a progressive inflammatory process of the biliary tree resulting in biliary obstruction. No single known genetic or environmental factor has been established to cause BA. Cystic fibrosis (CF) is a rare cause of neonatal cholestasis, and it has never been described in familial BA cases. Here, we investigate two siblings of first-degree consanguineous parents presenting with neonatal BA. Shortly after the Kasai operation, the proband developed severe respiratory symptoms attributable to a missed CF diagnosis. This was discovered after re-investigating the family history, which revealed a first-degree cousin with CF who did not manifest BA. Afterwards, we identified a pathogenic variant (DeltaF508) in CFTR in both BA-affected siblings along with their cousin. This intrigued us to study the molecular etiology behind the familial BA presentations, which exclusively contributed to BA-pathogenesis in BA-CF-affected siblings and not in their CF-only affected cousin. We applied a multistep approach to investigate the variant profile of both siblings' and their cousin's exomes. We curated the genes whose variants were shared by the BA-CF siblings but absent or heterozygous in their CF-only-affected cousin. Consequently, we identified three candidate genes (SNAPC4, UCK1, and ZHX2) besides CFTR. We propose that these genes act cumulatively or individually in inducing BA-pathogenesis-either by aggravating the biliary damage in the context of CF or increasing the susceptibility of BA as a separate CF-comorbidity. To our knowledge, this is the first report of DeltaF508 in CFTR with familial neonatal BA cases.

Potential Composite Digenic Contribution of NPC1 and NOD2 Leading to Atypical Lethal Niemann-Pick Type C with Initial Crohn’s Disease-like Presentation: Genotype-Phenotype Correlation Study

Niemann–Pick disease type C (NPC) is an autosomal recessive neurovisceral disease characterized by progressive neurodegeneration with variable involvement of multisystemic abnormalities. Crohn’s disease (CD) is an inflammatory bowel disease (IBD) with a multifactorial etiology influenced by variants in NOD2. Here, we investigated a patient with plausible multisystemic overlapping manifestations of both NPC and CD. Her initial hospitalization was due to a prolonged fever and non-bloody diarrhea. A few months later, she presented with recurrent skin tags and anal fissures. Later, her neurological and pulmonary systems progressively deteriorated, leading to her death at the age of three and a half years. Differential diagnosis of her disease encompassed a battery of clinical testing and genetic investigations. The patient’s clinical diagnosis was inconclusive. Specifically, the histopathological findings were directed towards an IBD disease. Nevertheless, the diagnosis of IBD was not consistent with the patient’s subsequent neurological and pulmonary deterioration. Consequently, we utilized a genetic analysis approach to guide the diagnosis of this vague condition. Our phenotype–genotype association attempts led to the identification of candidate disease-causing variants in both NOD2 and NPC1. In this study, we propose a potential composite digenic impact of these two genes as the underlying molecular etiology. This work lays the foundation for future functional and mechanistic studies to unravel the digenic role of NOD2 and NPC1.

The application of precision medicine in monogenic diabetes

INTRODUCTION

Monogenic diabetes, a form of diabetes mellitus, is caused by a mutation in a single gene and may account for 1-2% of all clinical forms of diabetes. To date, more than 40 loci have been associated with either isolated or syndromic monogenic diabetes.

AREAS COVERED

While the request of a genetic test is mandatory for cases with diabetes onset in the first 6 months of life, a decision may be difficult for childhood or adolescent diabetes. In an effort to assist the clinician in this task, we have grouped monogenic diabetes genes according to the age of onset (or incidental discovery) of hyperglycemia and described the additional clinical features found in syndromic diabetes. The therapeutic options available are reviewed.

EXPERT OPINION

Technical improvements in DNA sequencing allow for rapid, simultaneous analysis of all genes involved in monogenic diabetes, progressively shrinking the area of unsolved cases. However, the complexity of the analysis of genetic data requires close cooperation between the geneticist and the diabetologist, who should play a proactive role by providing a detailed clinical phenotype that might match a specific disease gene.

Effect of Genetic Testing on Diagnosing Gastrointestinal Pediatric Patients with Previously Undiagnosed Diseases

Purpose

Four consanguineous Jordanian families with affected members of unknown gastrointestinal related diseases were recruited to assess the utility and efficiency of whole exome sequencing (WES) in reaching the definitive diagnosis.

Patients and Methods

Members from four consanguineous Jordanian families were recruited in this study. Laboratory and imaging tests were used for initial diagnosis, followed by performing WES to test all affected members for the detection of causative variants. Sanger sequencing was used for validation.

Results

We had a 100% success rate identifying each case presented in this study.

Conclusion

This is the first study applying a WES testing approach in the diagnosis of pediatric diseases in Jordan. Our results strongly suggest the need to implement WES as an evident diagnostic tool in the clinical setting, as it will subsequently allow for proper disease management and genetic counseling.