Because the changes in blood carnitine and urinary organic acid spectra suggested MADD, whereas the clinical and routine biochemical changes indicated GSD Ia, Sanger sequencing (primers showed in Supplementary Table S1) on coding and flanking sequences of G6Pase and ETFDH from periphery blood sample was ordered for the patient and his parents. Here, G6PC1 is linked to multiple acyl-CoA dehydrogenase deficiency.