This study is a retrospective, case control study involving 535 preterm infants examining the roles of sequence polymorphisms in genes that mediate host immune responses to bacterial infection in newborn infants. A total of 49 single nucleotide polymorphisms (SNPs) in 19 candidate genes including inflammatory cytokines (IL6, IL10, IL1B, and TNF), cytokine receptors (IL1RN), toll-like receptors (TLR2, TLR4, and TLR5), and cell surface receptors (CD14) were genotyped. Subjects were stratified into three groups (sepsis, suspected sepsis, and control). The data were analyzed using a family-based transmission disequilibrium test. We found that birth weight, gestational age, duration of rupture of membranes, and presence of clinical chorioamnionitis were strongly associated with sepsis. Polymorphisms in TLR2 (rs3804099), TLR5 (rs5744105), IL10 (rs1800896), and PLA2G2A (rs1891320) genes were associated with sepsis. Allelic variants in PLA2G2A and TLR2 were associated with Gram-positive infections, whereas IL10 was associated with Gram-negative infections (p Ͻ 0.05). We conclude allelic variations in PLA2G2A, TLR2, TLR5, and IL10 may moderate the predisposition to sepsis in preterm infants. (Pediatr Res 68: 323-329, 2010)

Focal segmental glomerulosclerosis (FSGS) is the main pathology underlying steroid-resistant nephrotic syndrome (SRNS) and a leading cause of chronic kidney disease. Monogenic forms of pediatric SRNS are predominantly caused by recessive mutations, while the contribution of de novo variants (DNVs) to this trait is poorly understood. Using exome sequencing (ES) in a proband with FSGS/SRNS, developmental delay, and epilepsy, we discovered a nonsense DNV in TRIM8, which encodes the E3 ubiquitin ligase tripartite motif containing 8. To establish whether TRIM8 variants represent a cause of FSGS, we aggregated exome/genome-sequencing data for 2,501 pediatric FSGS/SRNS-affected individuals and 48,556 control subjects, detecting eight heterozygous TRIM8 truncating variants in affected subjects but none in control subjects (p ¼ 3.28 3 10 À11 ). In all six cases with available parental DNA, we demonstrated de novo inheritance (p ¼ 2.21 3 10 À15 ). Reverse phenotyping revealed neurodevelopmental disease in all eight families. We next analyzed ES from 9,067 individuals with epilepsy, yielding three additional families with truncating TRIM8 variants. Clinical review revealed FSGS in all. All TRIM8 variants cause protein truncation clustering within the last exon between residues 390 and 487 of the 551 amino acid protein, indicating a correlation between this syndrome and loss of the TRIM8 C-terminal region. Wild-type TRIM8 overexpressed in immortalized human podocytes and neuronal cells localized to nuclear bodies, while constructs harboring patient-specific variants mislocalized diffusely to the nucleoplasm. Co-localization studies demonstrated that Gemini and Cajal bodies frequently abut a TRIM8 nuclear body. Truncating TRIM8 DNVs cause a neuro-renal syndrome via aberrant TRIM8 localization, implicating nuclear bodies in FSGS and developmental brain disease.

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Background and Objectives Glomerulopathies affect kidney glomeruli and can lead to end‐stage renal disease if untreated. Clinical and experimental evidence have identified numerous (>20) genetic mutations in the mitochondrial coenzyme Q8B protein (COQ8B) primarily associated with nephrotic syndrome. Yet, little else is understood about COQ8B activity in renal pathogenesis and its role in mitochondrial dysfunction. We identified additional novel COQ8B mutations in a glomerulopathy patient and aimed to define the potential structural and functional defects of COQ8B mutations. Design, Setting, Participants, and Measurements Whole exome sequencing was performed on a Hispanic female presenting with proteinuria. Novel mutations in the COQ8B gene were identified. The effects of mutation on protein function, mitochondrial morphology, and disease progression were investigated by histopathology, transmission electron microscopy, homology modeling, and in silico structural analysis. Results We have characterized the pathophysiology of novel COQ8B mutations, compound heterozygous for two alterations c.1037T>G (p.I346S), and c.1560G>A (p.W520X), in the progression of proteinuria in a Hispanic female. Histopathology revealed defects in podocyte structure and mitochondrial morphology. In silico and computation analyses highlight possible structural origins of COQ8B dysfunction in the presence of mutations. Conclusions Novel mutations in COQ8B present promising biomarkers for the early detection and therapeutic targeting of mitochondrial glomerulopathy. Insights from structural modeling suggest roles of mutation‐dependent alterations in COQ8B allosteric regulation, protein folding, or stability in renal pathogenesis.