title: Ashy ears.
abstract: Alkaptonuria is a rare, autosomal-recessive disease of tyrosine degradation resulting from accumulation of homogentisic acid (HGA) within the body due to deficiency of the hepatic enzyme homogentisate 1,2-dioxygenase[1]. HGD is the gene encoding homogentisate 1,2-dioxygenase and is the only gene known to be associated with alkaptonuria. In this patient the disease also manifested itself with symmetric blue-gray discoloration on the helix cartilage of his ears. The initial diagnosis of alkaptonuria was made some 20 years earlier because of the appearance of low back pain and dark urine. HGA is responsible for the black color of urine and is deposited in the cartilage of the body, including ears.
authors.affiliation: Department of Dermatology, Veterans Administration Hospital (NIMTS), Athens, Greece. efrall@otenet.gr
authors.forename: Efstathios
authors.initials: E
authors.lastname: Rallis
authors.forename: Stephanos
authors.initials: S
authors.lastname: Kintzoglou
mesh_terms: D000474:Alkaptonuria / Q000150:complications / Q000175:diagnosis* / Q000235:genetics; D004423:Ear / Q000473:pathology*; D020022:Genetic Predisposition to Disease / Q000235:genetics; D050560:Homogentisate 1,2-Dioxygenase / Q000235:genetics / Q000378:metabolism*; D006713:Homogentisic Acid / Q000378:metabolism* / Q000652:urine; D006801:Humans; D008297:Male; D008875:Middle Aged; D010859:Pigmentation Disorders / Q000150:complications / Q000378:metabolism / Q000652:urine
chemical_list: D050560:Homogentisate 1,2-Dioxygenase; D006713:Homogentisic Acid