Neurocognitive outcome in young child with Isovaleric Acidemia

Abstract

Isovaleric Acidemia (IVA) is inherited as an autosomal recessive trait, caused by the deficiency of the enzyme isovaleryl CoA dehydrogenase. It has the prevalence of 1 in 62,500 (in parts of Germany) to 1 in 250,000 live births (in the United States). Acute episodes of metabolic decompensations may occur, which may mimic sepsis, ketosis or shock. Early diagnosis & early initiation of treatment has been reported to correlate with a good neurocognitive outcome. This is case of child presenting in Paediatric emergency department with fever, vomiting, increased respiratory activity and lethargy. Child had GCS score of 8/15, acidotic breathing, hypotonia with hyporeflexia. Sepsis screen, metabolic work up and neuroimaging were all normal except for high anion Gap acidosis with ketosis. So further neurometabolic screening work up was done in view of persistent metabolic acidosis, developmental delay, and bad obstetric history in mother. It revealed increased excretion of isovalerylglycine 1(IVG 1), Isovalerylglycine 2 (IVG2) Lactate, 3-Hydroxypropionate (3HP) and 3-Hydroxybutyrate (3 HB).Serum lactate 358.54 (control 1.1-208.1) confirming the diagnosis of Isovaleric Acidemia. After recovery from the acute attack, the patient was advised low-protein diet (1.0-1.5 g/kg/24 hrs.) and carnitine (100 mg/kg/24 hrs. orally) supplements. On follow up child is asymptomatic & showing neurological improvement as he started achieving further developmental milestones during 6 months follow up.

Early diagnosis and early treatment of IVA cases definitely results in favorable outcome and better prognosis. But chronic intermittent cases presenting late should not be neglected, proper medical management can reverse neuromotor consequences in them also.