Figure 1.

The TCA cycle, α-ketoglutarate complex enzymatic reaction and family pedigrees of investigated families. A. The TCA cycle with the OMIM phenotypes associated to each enzymatic complex listed. ∗ indicates OGDH deficiency that is described in this study. B. A schematic of the TCA cycle enzymatic reaction that OGDH catalyzes alongside DLD and DLST as the α-ketoglutarate dehydrogenase complex. C. Pedigrees of the 4 families harboring pathogenic OGDH variants. Affected individuals are indicated via filled symbols with implicated variant stated below. DLD, dihydrolipoamide dehydrogenase; DLST, dihydrolipoamide S-succinyltransferase; NAD, nicotinamide adenine dinucleotide; NADH, nicotinamide adenine dinucleotide hydrogen; OGDH, Oxoglutarate dehydrogenase; TCA, tricarboxylic acid.