NUP85 as a Neurodevelopmental Gene: From Podocyte to Neuron.

Pathogenic gene variants encoding nuclear pore complex (NPC) proteins were previously implicated in the pathogenesis of steroid-resistant nephrotic syndrome (SRNS). The NUP85 gene, encoding nucleoporin, is related to a very rare form of SRNS with limited genotype-phenotype information. We identified an Italian boy affected with an SRNS associated with severe neurodevelopmental impairment characterized by microcephaly, axial hypotonia, lack of achievement of motor milestones, and refractory seizures with an associated hypsarrhythmic pattern on electroencephalography. Brain magnetic resonance imaging (MRI) showed hypoplasia of the corpus callosum and a simplified gyration of the cerebral cortex. Since the age of 3 years, the boy was followed up at our Pediatric Nephrology Department for an SRNS, with a focal segmental glomerulosclerosis at renal biopsy. The boy died 32 months after SRNS onset, and a Whole-Exome Sequencing analysis revealed a novel compound heterozygous variant in NUP85 (NM_024844.5): 611T>A (p.Val204Glu), c.1904T>G (p.Leu635Arg), inherited from the father and mother, respectively. We delineated the clinical phenotypes of NUP85-related disorders, reviewed the affected individuals so far reported in the literature, and overall expanded both the phenotypic and the molecular spectrum associated with this ultra-rare genetic condition. Our study suggests a potential occurrence of severe neurological phenotypes as part of the NUP85-related clinical spectrum and highlights an important involvement of nucleoporin in brain developmental processes and neurological function.

Genetic Background and Molecular Mechanisms of Juvenile Idiopathic Arthritis.

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease in the paediatric population. JIA comprises a heterogeneous group of disorders with different onset patterns and clinical presentations with the only element in common being chronic joint inflammation. This review sought to evaluate the most relevant and up-to-date evidence on current knowledge regarding the pathogenesis of JIA subtypes to provide a better understanding of these disorders. Despite significant improvements over the past decade, the aetiology and molecular mechanisms of JIA remain unclear. It has been suggested that the immunopathogenesis is characterised by complex interactions between genetic background and environmental factors that may differ between JIA subtypes. Human leukocyte antigen (HLA) haplotypes and non-HLA genes play a crucial role in the abnormal activation of both innate and adaptive immune cells that cooperate in causing the inflammatory process. This results in the involvement of proinflammatory cytokines, including tumour necrosis factor (TNF)α, interleukin (IL)-1, IL-6, IL-10, IL-17, IL-21, IL-23, and others. These mediators, interacting with the surrounding tissue, cause cartilage stress and bone damage, including irreversible erosions. The purpose of this review is to provide a comprehensive overview of the genetic background and molecular mechanisms of JIA.

Diagnosis, treatment, and follow-up of a case of Wolman disease with hemophagocytic lymphohistiocytosis.

Wolman Disease (WD) is a severe multi-system metabolic disease due to lysosomal acid lipase (LAL) deficiency. We report on a WD infant who developed an unusual hemophagocytic lymphohistiocytosis (HLH) phenotype related to WD treated with sebelipase alfa. A male baby came to our attention at six months of life for respiratory insufficiency and sepsis, abdominal distension, severe hepatosplenomegaly, diarrhea, and severe growth retardation. HLH was diagnosed and treated with intravenous immunoglobulin, steroids, cyclosporine, broad-spectrum antimicrobial therapy, and finally with the anti-IL-6 drug tocilizumab. WD was suspected for the presence of adrenal calcifications and it was confirmed by LAL enzyme activity and by molecular analysis of LIPA. Plasma oxysterols cholestan-3ß,5α,6ß-triol (C-triol), and 7-ketocholesterol (7-KC) were markedly increased. Sebelipase alfa was started with progressive amelioration of biochemical and clinical features. The child died from sepsis, 2 months after sebelipase discontinuation requested by parents. Our case shows the importance of an early diagnosis of WD and confirms the difficulty to reach a diagnosis in the HLH phenotype. Sebelipase alpha is an effective treatment for LAL deficiency, also in children affected by WD. Further data are necessary to confirm the utility of measuring plasma c-triol as a biochemical marker of the disease.