Table 1

Causes of hyperammonaemia according to age in this cohort of patients

<1 mth1–12 mth1–16 yTotal
Results expressed as number of cases.
Urea cycle defects176528
Branched chain organic acidaemias9009
Tyrosinaemia type 1 (with liver failure)0314
Congenital lactic acidoses1203
Hyperinsulinism with hyperammonaemia1012
Carnitine transporter defect0101
Glutaric aciduria type I0011
Congenital defect of glycosylation0011
Transient hyperammonaemia of the newborn2002
Liver failure (without inborn error)0123
    Repeat ammonia normal91717
    Patient died (no repeat measurement)3306
    No repeat measurement53513