Benign familial hematuria associated with a novel COL4A4 mutation.

We describe a father and three offspring with hematuria. The father and one girl also complained of flank pain. Renal function tests and ophthalmological examinations were normal in all. The father had very mild neural deafness. The renal biopsy samples of two affected siblings showed changes compatible with thin basement membrane disease. Genetic analysis revealed a novel missense mutation in exon 32 of COL4A4 to be responsible for the phenotype in this family. We suggest that thin basement membrane disease may have overlapping clinical features with other causes of hematuria; genetic analysis may help in the differential diagnosis and help us further understand the disease processes.