COL4A4 and hematuria, benign familial, 1: Alterations in the COL4A3, COL4A4 and COL4A5 genes are associated with glomerular basement membrane-related diseases, such as autosomal recessive Alport syndrome (Storey et al., 2013; Hudson et al., 2003), familial focal segmental glomerulosclerosis (Andrew et al., 2014), and thin basement membrane nephropathy (Wang et al., 2004).