Glutaric acidemia type II (GA II), also known as multiple acyl-CoA dehydrogenase deficiency, is an auto-somal recessive inborn error of amino acid and fatty acid metabolism. We report a case of GA. with novel electron transfer flavoprotein (ETF)-A mutations in a 2-year-old female with thalassemia minor. The patient developed an episode of hypoglycemia and hypotonicity on the postnatal first day. Laboratory investigations revealed elevations of multiple acyl carnitines indicating glutaric acidemia type II in newborn screening analysis. Urinary organic acids were evaluated for the confirmation and revealed a high glutaric acid excretion. Genetic analysis revealed two novel mutations in the ETF-A gene, which are considered to be compound heterozygote. At the 8 mo of life ketone therapy was added, which significantly increased the neuromotor development. The patient had been closely followed for two years with carnitine, riboflavin, coenzyme Q10, and ketone supplementation in addition to a high carbohydrate diet. Although the patient had comorbidity like thalassemia minor, her neuromotor development was normal for her age and had no major health problems. This specific case expands the previously reported spectrum of this disease.