Citrullinemia with an atypical presentation: persistent hiccups. Case report

Area of Science:

• Biochemistry
• Neonatology
• Genetics

Background:

• Encephalopathy in neonates presents a diagnostic challenge.
• Inborn errors of metabolism can manifest with neurological symptoms and hiccups.

Observation:

• A neonate presented with encephalopathy and persistent hiccups within 72 hours of life.
• Initial sepsis workup and CSF analysis were unremarkable.

Findings:

• Metabolic evaluation revealed hyperammonemia and hypercitrullinemia.
• Normal CSF/plasma glycine ratio excluded nonketotic hyperglycinemia.
• Argininosuccinic acid synthetase deficiency (ASD; citrullinemia) was diagnosed.

Implications:

• Neonatal onset ASD should be considered in the differential diagnosis of encephalopathy with hiccups.
• Early identification of metabolic disorders is crucial for timely intervention.
• This case highlights the importance of comprehensive metabolic screening in neonates with unexplained neurological symptoms.