"Mrs. G" — a lifetime of episodes, and one ammonia level

What happened

A woman known in the literature as Mrs. G lived with recurrent episodes that were read through a psychiatric lens for years before anyone found the metabolic cause: a partial deficiency of CPS1, an enzyme in the urea cycle — the body's system for clearing ammonia.

What it looked like

Episodes of altered mental state and psychiatric-type symptoms that came and went, the pattern urea-cycle disorders are known for: fine between episodes, very unwell during them.

What the labs found

During an episode, her ammonia was 224 — dangerously high. Her body could not clear nitrogen waste, and the ammonia was poisoning her brain.

What changed

On treatment to control her ammonia, her level fell to 19 and she was reported symptom-free at six months.

An important caution this library will repeat: in liver disease, a single ammonia number does not grade how severe brain symptoms are (Bajaj 2024, Clinical Gastroenterology and Hepatology). Ammonia matters — it just isn't a severity score.