Background: Hyperammonemia and hyperlactatemia in neonates and young children with non-specific biochemical markers poses a diagnostic challenge. An accurate diagnosis is essential for effective management.
Case reports: We present three infants from unrelated families, one with infantile and two with neonatal hyperammonemic encephalopathy, hypoglycaemia, and hyperlactatemia. The underlying cause was confirmed following whole exome sequencing as biochemical markers were not conclusive of a definite diagnosis.
Conclusion: The combination of hyperammonemic encephalopathy, hyperlactatemia and hypoglycemia in neonates and infants should prompt physicians to suspect Carbonic anhydrase VA deficiency. Majority of these children can have a favourable long-term outcome with symptomatic treatment.
Keywords: CA-VA; CA5A; Carbonic anhydrase deficiency; Hyperammonemia; Hyperlactatemia; Mitochondrial.
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