Our data confirm for the first time a definite association of heterozygous COL4A3/COL4A4 mutations with familial microscopic haematuria, thin basement membrane nephropathy and the late development of familial proteinuria, CRF, and ESRD, due to FSGS, indicating that the term 'benign familial haematuria' is a misnomer, at least in this cohort.
In addition, levels of PTCH (patched) mRNA were increased relative to unremarkable epidermis in familial BFH lesions but to a lesser degree and in a different pattern than that seen in BCC.
On electron microscopy, thickness of the glomerular basement membrane (BGM) was found to distinguish benign familial hematuria (BFH - 10 cases) from non familial idiopathic recurrent hematuria (IRH - 9 cases).