Molecular Genetic Testing for Kidney Disorders During the COVID-19 Pandemic

Chronic kidney disease (CKD) has major morbidity and mortality for children and adults. While in adults CKD often is associated with diabetic complications, genetic variants can be the underlying cause in both populations. Beginning in 2016 with the emergence of more affordable next-generation sequencing (NGS) technologies, the Molecular Diagnostics Lab at Nemours Children's Hospital-Delaware developed the first clinically actionable pediatric NGS kidney panel comprised of 46 genes including APOL1. Apolipoprotein L1 (APOL1) associated nephropathy is reported along a spectrum of non-diabetic kidney disease. It is significantly associated with two "risk alleles" defined as G1 and G2 and typically found in individuals of African descent. In early 2020, as COVID-19 spread across the globe, reports of patients with kidney failure began to emerge. A collapsing glomerulopathy in Black patients with COVID-19 was found to be associated with the APOL1 predisposition of the known G1 and/or G2 risk variants. We identified genetic variants in 11 genes (NPHS1; NPHS2; LAMB2; WT1; COL4A4; COL4A5; COQ8B; CUBN; MEFV; PMM2; SMARCAL1) known to be associated with pediatric onset nephrotic syndrome, or detection of the high-risk haplotype of APOL1, in the majority (78%) of patients tested. These clinically actionable results guided medical care and improved patient outcomes.