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 ophthalmologi cal examinations were normal in all. The father had very mild neural deafne ss. The renal biopsy samples of two affected siblings showed changes compat ible 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 ov erlapping clinical features with other causes of hematuria:, genetic analys is may help in the differential diagnosis and help us further understand th e disease processes.