Some types of acute porphyrias cause muscle weakness. Muscle problems can be life-threatening if weakness affects the muscles that make respiration (breathing) possible.
[my.clevelandclinic.org]
Besides having abdominal and nerve pain, the patient may suffer rapid heartbeat, mania, muscle cramps, muscle weakness, breathing problems, hallucinations, and coma.
[rxlist.com]
Acute porphyria can also affect the nervous system causing numbness and muscle weakness.
[recordatirarediseases.com]