Ratios of long-chain acylcarnitines such as palmitoylcarnitine (C16), octadecenoylcarnitine (C18:1) and the carnitine conjugate of the end-product of the TCA-cycle acetyl-CoA, acetylcarintine (C2), can be used to diagnose CPT2 deficiency [16]. This evidence concerns the gene CPT2 and hyperinsulinemic hypoglycemia, familial, 4.