Abstract Kidney anomalies (KA) are developmental disorders that commonly cause pediatric chronic kidney disease and mortality. We examined rare coding variants in 248 KA trios and 1,742 singleton KA cases and compared them to 22,258 controls. Diagnostic and candidate diagnostic variants were detected in 14.1% of cases. We detected a significant enrichment of rare damaging variants in constrained genes expressed during kidney development and in genes associated with other developmental disorders, suggesting phenotype expansion. Consistent with these data, 18% of KA patients with diagnostic variants had neurodevelopmental or cardiac phenotypes. Extrarenal developmental phenotypes were associated with a higher burden of rare variants. Statistical analyses identified 40 novel candidate genes, 2 of which were confirmed as new KA genes: ARID3A and NR6A1. This study suggests that many yet-unidentified syndromes would be discoverable with larger cohorts and cross-phenotype analysis, leading to clarification of the genetic and phenotypic spectrum of developmental disorders.
Glomerular diseases are characterized by variable disease activity over many years. We aimed to analyze the relationship between clinical disease activity and duration of glomerular disease.Disease activity in adults with chronic minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, and IgA nephropathy (IgAN; first diagnostic biopsy >5 years before enrollment; Of Longstanding Disease [OLD] cohort, n = 256) followed at Columbia University Medical Center (CUMC), was compared with disease activity of an internal and external cohort of patients with first diagnostic biopsy <5 years before enrollment drawn from the Cure Glomerulonephropathy Network (CureGN cohort, n = 1182; CUMC-CureGN cohort, n = 362). Disease activity was defined by (i) Kidney Disease: Improving Global Outcomes-recommended threshold criteria for initiation of immunosuppression in primary glomerulonephropathy (GN) and (ii) CureGN's Disease Activity Working Group definitions for activity.No significant differences were detected among the 3 cohorts in terms of age, sex, serum creatinine, and urinary protein-to-creatinine ratio. For each GN subtype, disease activity in the OLD cohort was comparable with disease activity in the entire CureGN and the CUMC-CureGN cohort. When limiting our comparisons to disease activity in incident CUMC-CureGN patients (first diagnostic biopsy within 6 months of enrollment), OLD patients demonstrated similar activity rates as incident patients.Disease activity did not differ among patients with shorter versus longer duration of disease. Such survivor patients, with long-term but persistent disease, are potentially highly informative for understanding the clinical course and pathogenesis of GN and may help identify factors mediating more chronic subtypes of disease.
Significance Statement Vesicoureteral reflux (VUR) is associated with progressive kidney disease. Familial aggregation supports a hereditary basis; however, its genetic architecture remains to be elucidated. The largest VUR copy number variant analysis and genome-wide association study to date accounts for multiple modes of inheritance and sex-specific effects in VUR, identifying three study-wide significant and five suggestive loci with large effects, containing canonical developmental genes including WDPCP and WNT5A . Results of experiments in mice support novel roles of Wnt5a in urogenital development. Altogether, 6% of patients carried high-risk genotypes. These findings have important implications for VUR screening. Background Vesicoureteral reflux (VUR) is a common, familial genitourinary disorder, and a major cause of pediatric urinary tract infection (UTI) and kidney failure. The genetic basis of VUR is not well understood. Methods A diagnostic analysis sought rare, pathogenic copy number variant (CNV) disorders among 1737 patients with VUR. A GWAS was performed in 1395 patients and 5366 controls, of European ancestry. Results Altogether, 3% of VUR patients harbored an undiagnosed rare CNV disorder, such as the 1q21.1, 16p11.2, 22q11.21, and triple X syndromes ((OR, 3.12; 95% CI, 2.10 to 4.54; P =6.35×10 −8 ) The GWAS identified three study-wide significant and five suggestive loci with large effects (ORs, 1.41–6.9), containing canonical developmental genes expressed in the developing urinary tract ( WDPCP, OTX1, BMP5, VANGL1, and WNT5A ). In particular, 3.3% of VUR patients were homozygous for an intronic variant in WDPCP (rs13013890; OR, 3.65; 95% CI, 2.39 to 5.56; P =1.86×10 –9 ). This locus was associated with multiple genitourinary phenotypes in the UK Biobank and eMERGE studies. Analysis of Wnt5a mutant mice confirmed the role of Wnt5a signaling in bladder and ureteric morphogenesis. Conclusions These data demonstrate the genetic heterogeneity of VUR. Altogether, 6% of patients with VUR harbored a rare CNV or a common variant genotype conferring an OR >3. Identification of these genetic risk factors has multiple implications for clinical care and for analysis of outcomes in VUR.
Membranous nephropathy (MN) is a leading cause of nephrotic syndrome in white adults. Approximately 70% of MN cases are considered primary; the remaining 30% of cases are considered secondary to systemic conditions, such as lupus, hepatitis B, and solid tumors. In the last decade, target antigens and their associated autoantibodies, which are responsible for the development of primary MN cases, have been identified. The M-type phospholipase A2 receptor (PLA2R) is the specific podocyte antigen responsible for eliciting immune complex formation with circulating autoantibodies in most (∼75%−80%) primary MN cases.
