Hawkinsin

Hawkinsinuria is a rare inborn error of metabolism characterized by the excretion of hawkinsin, a heterocyclic organic compound, in the urine. This condition is inherited in an autosomal dominant manner and is caused by mutations in the 4-hydroxyphenylpyruvate dioxygenase (HPD) gene. The HPD gene is crucial for the normal breakdown of the amino acid tyrosine, and mutations in this gene lead to the accumulation and excretion of abnormal metabolites, including hawkinsin.

The clinical presentation of hawkinsinuria can vary, but it typically includes transient metabolic acidosis in infancy, which may be accompanied by failure to thrive, hypoglycemia, and sometimes, liver dysfunction. However, most affected individuals recover from the acute metabolic disturbances in infancy and often do not exhibit significant health issues later in life.

The diagnosis of hawkinsinuria is based on the detection of hawkinsin in the urine, alongside genetic testing to identify mutations in the HPD gene. Management and treatment of hawkinsinuria primarily involve dietary restrictions to limit tyrosine intake, thereby reducing the production of toxic metabolites. This may include a diet low in protein or the use of specialized formulas in infants.

Given its rarity, hawkinsinuria is a condition that may not be immediately recognized by healthcare providers, and it underscores the importance of metabolic screening in infants presenting with unexplained metabolic acidosis and failure to thrive.