TBMN is usually caused by mutations in the genes encoding for type IV collagen, which is an essential component of the GBM. The most common genes involved are COL4A3 and COL4A4. These mutations result in a structurally weaker GBM, which is prone to becoming thin. The condition often follows an autosomal dominant inheritance pattern, meaning that a single copy of the altered gene in each cell is sufficient to cause the disorder.
