[MIM*276800] A very rare, possibly heritable disorder of tyrosine metabolism that may be caused by defective formation of p-hydroxyphenylpyruvic acid oxidase or of tyrosine transaminase; characterized by enhanced urinary excretion of p-hydroxyphenylpyruvic acid and of other tyrosyl metabolites upon ingestion of tyrosine or proteins containing that amino acid; of autosomal recessive inheritance. [tyrosine + G. -osis, condition]