HGD and alkaptonuria: We found SAA amyloidosis as a life-threatening complication inalkaptonuria (AKU) [1], an ultra-rare(1:250.000-1.000.000 incidence) autosomal recessive genetic disease due to adeficient activity of homogentisate 1,2-dioxygenase (HGD) leading to theaccumulation of homogentisic acid (HGA).