Management of porphyria-like syndrome in tyrosinemia type 1

Hereditary tyrosinemia type 1 (HT1) is a rare metabolic disorder that may present with severe hepatic and neurological complications. Acute porphyria-like crises in HT1 are extremely uncommon and may be associated with severe electrolyte disturbances such as hyponatremia due to the syndrome of inappropriate antidiuretic hormone secretion (SIADH).

We describe a 9-year-old girl with genetically confirmed HT1 who developed an acute porphyria-like crisis accompanied by severe symptomatic hyponatremia secondary to SIADH. The patient presented with abdominal pain, vomiting, and progressive neurological deterioration culminating in generalized tonic-clonic seizures. Laboratory evaluation revealed profound hyponatremia, elevated urinary succinylacetone, and increased porphyrin precursors. Management included intravenous hemin therapy, fluid restriction, and intensive care support, leading to full neurological recovery without sequelae.

To our knowledge, this is the first reported case in Türkiye successfully managed with hemin during an acute porphyria-like episode in HT1 and only the second documented case of SIADH in this context. This case underscores the importance of recognizing SIADH and optimizing fluid management in patients with HT1 presenting with acute neurological crises.