Table 4. Fatty acid metabolism disordersa (°=Primary markers).
| Medium chain acyl co-A dehydrogenase deficency (MCAD) |
| °Elevated C8 (octanooyl carnitine) |
| °Elevated C8/C10 |
| Medium chain ketoacyl co-A thiolase deficency |
| °Elevated C8 (octanooyl carnitine) |
| °Elevated C6DC (adpyl carnitine) |
| Short chain acyl co-A dehydrogenase deficency (SCAD) |
| °Elevated C4 (butyryl carnitine) |
| Medium and short chain acyl co-A dehydrogenase deficency (M/SCHAD) |
| °Elevated C4OH (3-OH butyryl carnitine) |
| Dienoyl co-A reductase deficency |
| °Elevated C10:2 (decadienoyl carnitine) |
| Long chain 3-OH acyl co-A dehydrogenate deficency (LCHAD) |
| °Elevated C16-OH (3-OH palmitoyl carnitine) |
| Very long chain acyl co-A dehydrogenase deficency (VLCAD) |
| °Elevated C14:1 (tetradecenoyl carnitine) |
| °Elevated C14:1/C12:1 |
| °Elevated C14:1/C16 |
| Acyl co-A dehydrogenase deficency /glutaric acidurin type II (MAD/GA II) |
| °Elevated C4 (butyryl carnitine) |
| °Elevated C5 (isovaleryl carnitine) |
| Carnitine uptake/transport deficency |
| °Low free carnitine |
| Carnitine palmitoyl transferase I deficency (CPT I) |
| °Elevated free carnitine/C16 + C18 |
| Carnitine palmitoyl transferase II deficency (CPT II) |
| °Elevated C16 (palmitoyl carnitine) |
| °Elevated C18:1 (oleyl carnitine) |
| Carnitine/acylcarnitine translocase deficency (CACT) |
| °Elevated C16 (palmitoyl carnitine) |
| °Elevated C18:1 (oleyl carnitine) |
a
Fatty acids metabolic disorders show elevated levels of certain acyl-carnitines at birth, but in neonates with Carnitine Uptake/Transport deficency (CU/TD), the levels of free carnitine are low (see CU/TD highlighted in the table). At the light of our findings of low levels of free carnitine in neonates who then developed T1D, we wonder whether children affected by CU/TD develop T1D more often than expected.