Fig. 1.

A. Study patients. B. The family trees of de novo cases. The probands of families 1, 2, 3 and 4 were classically affected male patients and that of family 5 was a female heterozygote patient. The parents of probands in these 5 families had no characteristic symptoms of FD. All of the probands had disease-causing mutations and these mutations were not detected from their parents and siblings.