Causes of hyperammonaemia according to age in this cohort of patients
| Age | ||||
|---|---|---|---|---|
| <1 mth | 1–12 mth | 1–16 y | Total | |
| Results expressed as number of cases. | ||||
| Urea cycle defects | 17 | 6 | 5 | 28 |
| Branched chain organic acidaemias | 9 | 0 | 0 | 9 |
| Tyrosinaemia type 1 (with liver failure) | 0 | 3 | 1 | 4 |
| Congenital lactic acidoses | 1 | 2 | 0 | 3 |
| Hyperinsulinism with hyperammonaemia | 1 | 0 | 1 | 2 |
| Carnitine transporter defect | 0 | 1 | 0 | 1 |
| Glutaric aciduria type I | 0 | 0 | 1 | 1 |
| Congenital defect of glycosylation | 0 | 0 | 1 | 1 |
| Transient hyperammonaemia of the newborn | 2 | 0 | 0 | 2 |
| Liver failure (without inborn error) | 0 | 1 | 2 | 3 |
| Unexplained | ||||
| Repeat ammonia normal | 9 | 1 | 7 | 17 |
| Patient died (no repeat measurement) | 3 | 3 | 0 | 6 |
| No repeat measurement | 5 | 3 | 5 | 13 |