Diagnosis is primarily clinical. Routine serum chemistry panel should be checked.
Other Laboratory Studies
Newborn Screening
Serum Biotinidase Activity decreased
Serum Ammonia Levels increased
Plasma Carnitine
Quantitative Amino Acid levels
Urine B-Hydroxyisoverlate decreased
Urine Biotin decreased
Urine Ketones increased
Newborn Screening
Serum Biotinidase Activity decreased
Serum Ammonia Levels increased
Plasma Carnitine
Quantitative Amino Acid levels
Urine B-Hydroxyisoverlate decreased
Urine Biotin decreased
Urine Ketones increased
Vitamin B7 deficiency
DDx involves genetic disorders with impaired carboxylation.
Vitamin B9 deficiency
Biotinidase Deficiency 
Vitamin B12 deficiency
Holocarboxylase Synthetase Deficiency 
Vitamin A deficiency
Carnitine Deficiency