Specifically it is this: https://en.wikipedia.org/wiki/Carbamoyl_phosphate_synthetase_I_deficiency https://en.wikipedia.org/wiki/Carbamoyl_phosphate_synthetase.

Specifically it is this: https://en.wikipedia.org/wiki/Carbamoyl_phosphate_synthetase_I_deficiency https://en.wikipedia.org/wiki/Carbamoyl_phosphate_synthetase... People born with this lack the enzyme CPS1, which screws up the urea cycle and causes a build up of ammonia. Ammonia build up is bad for your nervous system.