Benign familial hematuria (BFH) is an autosomal dominant condition manifest as nonprogressive isolated microscopic hematuria that does not result in renal failure. It is characterized pathologically by thinning of the glomerular basement membrane (GBM), and can be considered the mildest end of the spectrum of renal diseases due to type IV collagen defects of the basement membrane. The most severe end of the spectrum is represented by Alport syndrome (see 301050), which results in end-stage renal failure and may be associated with hearing loss and ocular anomalies (review by Lemmink et al. (1996)). For a discussion of genetic heterogeneity of BFH, see BFH1 (141200).