investigations
Last reviewed 01/2018
Investigations include:
- biochemistry - hyponatraemia, hypomagnesaemia and hypovolaemia may occur during acute attacks
- definitive test is porphobilinogen deaminase in erythrocytes which is decreased by 50%
- urine - usually normal colouration when fresh but becomes brown, red or black on standing; marked increase in porphobilinogen (PBG); slightly elevated coproporphyrin and uroporphyrin
- stool - coproporphyrin and protoporphyrin normal
- liver function tests - sulfobromophthalein retention
- increased serum cholesterol, serum iron and T4
- hyperbetalipoproteinemia
- abnormal glucose tolerance