tyrosinosis

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]

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ty·ro·sin·osis .tī-rō-si-'nō-səs n a condition of faulty metabolism of tyrosine marked by the excretion of unusual amounts of tyrosine in the urine

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n.

an inborn defect of metabolism of the amino acid tyrosine that causes excessive excretion of parahydroxyphenylpyruvic acid in the urine, giving it abnormal reducing power.

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ty·ro·sin·o·sis (ti″ro-sĭ-noґsis) abnormal accumulation of tyrosine; the term is usually used to denote type I tyrosinemia. However, it is sometimes used to describe a single case of abnormal tyrosine metabolism characterized by myasthenia gravis but neither hepatorenal nor oculocutaneous signs and elevated urinary 4-hydroxyphenylpyruvic acid; the presentation was atypical but it was never biochemically classified.