Long-term follow up of a new case of hawkinsinuria.
Hawkinsinuria is a rarely diagnosed autosomal dominantly transmitted inborn error of tyrosine metabolism with impaired conversion of 4-hydroxyphenylpyruvate to homogentisate. As a consequence of the defective 4-hydroxyphenylpyruvate dioxigenase activity, large amounts of the unusual, ninhydrin-positive amino acid hawkinsin and later on in life 4-hydroxycyclohexylacetic acid are formed and excreted. Clinically the disease is characterised mainly by chronic metabolic acidosis and severe growth retardation as a result of protein overload. As the ability to form 4-hydroxycyclohexylacetic acid and thereby to cope with the still not very well defined reactive and toxic intermediates increases, clinical symptoms vanish. We report here a new patient with hawkinsinuria having experienced a series of admissions because of unclear hepatopathy, growth retardation, and renal tubular acidosis.


CONCLUSIONS
Prolonged tyrosyluria in the newborn and young baby should cause the clinical chemist not only to exclude tyrosinaemia, galactosaemia, and fructose intolerance but also to look carefully for hawkinsin in the aminoacid chromatogram.
Lehnert
W
W
University Children's Hospital, Metabolic unit, Freiburg, Germany. Lehnert@kk1200.ukl.uni-freiburg.de
Stögmann
W
W
Engelke
U
U
Wevers
R A
RA
van den Berg
G B
GB
D015111:4-Hydroxyphenylpyruvate Dioxygenase / Q000378:metabolism; D000141:Acidosis, Renal Tubular / Q000175:diagnosis / Q000209:etiology; D000592:Amino Acid Metabolism, Inborn Errors / Q000175:diagnosis* / Q000235:genetics* / Q000378:metabolism; D000603:Amino Acids, Sulfur / Q000652:urine*; D053138:Cyclohexenes; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D005633:Fructose Intolerance / Q000175:diagnosis; D006130:Growth Disorders / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D007223:Infant; D008107:Liver Diseases / Q000175:diagnosis / Q000209:etiology; D008297:Male; D014443:Tyrosine / Q000097:blood*
D000603:Amino Acids, Sulfur; D053138:Cyclohexenes; D014443:Tyrosine; C014578:hawkinsin; D015111:4-Hydroxyphenylpyruvate Dioxygenase