EC Paediatrics

Background: Hereditary tyrosinaemia type 1 (HT1) is a rare autosomal recessive disorder with variable manifestations. This study aimed to describe clinical and biochemical features of HT1 in Moroccan children.

Methods: This retrospective study included children diagnosed with HT1 and followed at Mohammed V Military Teaching Hospital, Rabat, Morocco, between January 2007 and December 2024. Data were collected using standardised forms covering clinical, biochemical, therapeutic and outcome parameters. Diagnosis was confirmed by elevated succinylacetone.

Results: Ten patients from nine families were included (six females, four males). Consanguinity was present in all cases (first-degree 70%, second-degree 30%). Seven patients (70%) had the acute form and three (30%) the chronic form. Mean age at diagnosis was 8.3 months for acute cases and 62 months for chronic cases. Common presenting signs were abdominal distension (50%) and hepatomegaly (30%). All patients developed hepatic insufficiency; hepatomegaly and growth failure occurred in 90%. Nine patients (90%) received nitisinone. Outcomes were favourable in 70%, while 20% died from hepatic failure.

Conclusion: This study represents the largest paediatric HT1 cohort from Morocco, highlighting the role of consanguinity and delayed diagnosis. Early nitisinone therapy improved outcomes, underscoring the need for diagnostic awareness and newborn screening.

 Keywords: Tyrosinemias; Nitisinone; Succinylacetone; Children; Metabolism; Pediatrics

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