P146: Real-world characterization of Alport syndrome in a specialized renal genetics clinic

Alport syndrome (AS) is a genetically heterogeneous disorder caused by pathogenic variants in the type IV collagen genes (COL4A3, COL4A4, and COL4A5), which encode the α3, α4, and α5 chains of type IV collagen—a critical structural component of basement membranes in the kidney, cochlea, and eye. Clinically, AS is characterized by hematuria, proteinuria, chronic kidney disease, hearing loss, and ocular abnormalities. Historically, X-linked AS, caused by pathogenic variants in COL4A5, has been considered the most common form, accounting for more than 70% of cases, followed by autosomal recessive AS resulting from homozygous or compound heterozygous pathogenic variants in COL4A3 or COL4A4.