COL4A4 and focal segmental glomerulosclerosis: Moreover, a recent clinicopathological report on 127 patients from 11 large pedigrees found a definite association of heterozygous COL4A3/COL4A4 mutations with familial microscopic hematuria, chronic renal failure and end stage renal disease, due to FSGS, suggesting that the term “benign familial hematuria” is a misnomer, at least in their cohort (19,20).