[1][2] Normally, the breakdown of the amino acid tyrosine involves the conversion of 4-hydroxyphenylpyruvate to homogentisate by 4-hydroxyphenylpyruvate dioxygenase.

The intermediate then spontaneously reacts with glutathione to form 2-L-cystein-S-yl-1,4-dihydroxy-cyclohex-5-en-1-yl acetic acid (hawkinsin).

[3][4] Patients present with metabolic acidosis during the first year of life, and growth arrest around the time of weaning off breast milk.

Patients have a normal life and do not require treatment or a special diet.

Inheritance of hawkinsinuria is therefore autosomal dominant (presence of a single mutated copy of the gene causes the condition).