Update on APOL1 and chronic kidney diseases in children.

Chronic kidney disease (CKD) is a major global health burden that disproportionately impacts people of recent African ancestry. The discovery of risk variants in the apolipoprotein L1 (APOL1) gene has transformed the understanding of racial disparities in CKD. In particular, APOL1 variants have been associated with increased risk of focal segmental glomerulosclerosis, virus-associated nephropathy, and other glomerular diseases in Black adults. While approximately 10-15% of Black Americans have a high-risk APOL1 genotype, disease penetrance is variable and is likely mediated by additional genetic and environmental "second hits." Variants in APOL1 have also been implicated in kidney transplant outcomes and pregnancy complications, underscoring its broad clinical relevance. Advances in therapeutic strategies, including small molecule inhibitors of APOL1 pore function, APOL1 antisense oligonucleotides, and JAK-STAT pathway modulation, offer promise for targeted interventions in adult populations. Emerging data in children highlight similar genotype-phenotype associations, with evidence of high-risk APOL1 genotype impacting steroid-resistant nephrotic syndrome and CKD progression. However, pediatric studies remain limited and underpowered, leaving critical gaps in the understanding of disease epidemiology, mechanisms, and long-term outcomes. This review will explore current knowledge of APOL1 kidney disease (AMKD) with a particular focus on pediatric populations and highlight the need for inclusion of children in future studies.