One Thursday night we received an excited phone call from a urologist in private practice asking us to have a look at the strange “strawberry yoghurt-like” urine of a 13-year-old girl. We were curious to see both urine and girl the same night and met a fit and healthy-looking 13-year-old Bavarian girl with a 6-week history of intermittent flank pain and thick, “strawberry yoghurt-like” urine (Fig. 1). She had been discharged from an external hospital 4 weeks earlier with the diagnosis of nephritic proteinuria and microhematuria.