HMGCL and hyperinsulinemic hypoglycemia, familial, 4: The rare organic acidurias diagnosed were 2-methyl-3-hydroxybutyric aciduria, 2-hydroxy glutaric aciduria, oxoprolinuria, 3-methylglutaconic aciduria type 5, HMG CoA lyase deficiency, riboflavin deficiency, etc. A seven-month-old girl child with metabolic encephalopathy was diagnosed with 2-methyl-3-hydroxybutyric aciduria, which is an X-linked dominant rare IEM and is not reported in India.