Rare Complication of Hereditary Tyrosinemia Type 1: Neurogenic Crisis

renal tubular dysfunction, and growth retardation. Neurogenic crisis accompanied by rare and life-threatening encephalopathy, seizure, severe abdominal pain, and respiratory problems may occur in patients who are not treated adequately to provide disease control with nitisinone, supportive treatments, phenylalanine and tyrosine-restricted diet.

We aimed to share the diagnosis, clinical and follow-up information for this rare and life-threatening complication.

Methods: Six (15%) of the 38 tyrosinemia cases in our follow-up showed neurogenic crisis. Clinical, laboratory, and therapeutic data related to neurogenic crises were retrospectively evaluated from their medical records.

Results: The mean age at diagnosis was 8.3 ± 1.8 months (7−11), and nitisinone and phenylalanine-tyrosine restricted diet were started in all cases at the time of diagnosis. The mean age of development of neurogenic crisis was 84 ± 46 months (38−160) and the patients interrupted nitisinone treatment and diet mean was 23±17 days (3−45).

The first symptom of all cases was abdominal pain, altered consciousness, and 5 cases had seizures. All cases were encephalopathic and hypertensive at the first admission. Laboratory results showed hyponatremia in 4 cases, urine succinylacetone in 2 cases, blood succinyl acetone in 4 cases, and urinary aminolevulinic acid levels in 5 cases were high. Two cerebral MRIs revealed the presence of PRESS. Tracheostomy was required in one case due to severe respiratory failure.

Discussion/conclusion: In untreated patients, increased delta aminolevulenic acid levels at the end of porphobilinogen synthase blooms cause severe porphyry-like abdominal pain. Although there is no clear laboratory data for this life-threatening clinical event, the most important diagnostic finding is clinical, nitisinone treatment and supportive treatment should be started urgently.