chempath - porphyria

Question 1

3 main features of porphyrias

Answer 1

1) microcytic anaemia
2) Neurovisceral sx
3) Cutaneous sx

Question 2

Acute Intermittent Porphyria - what is the main defect?

Answer 2

HMB synthase aka PBG deaminase deficiency

Question 3

What accumulates in AIP?

Answer 3

5-ALA

Question 4

Rate limiting step in haem biosyntehsis

Answer 4

ALA-synthase activity

Question 5

Typical presentation of AIP

Answer 5

Trigger: EtOH, drugs, infection, surgery, starvation

• ONLY NEUROVISCERAL SX
• Seizures/sensory loss
• N+V/hypertension/tachycardia/urinary incontinence

Question 6

Dx of Acute Intermittent Porphyria

Answer 6

Urine ALA and PBG

Question 7

Appearance of urine in AIP

Answer 7

Port wine

Question 8

Tx of Acute intermittent porphyria

Answer 8

IV dextrose + haem arginate

Question 9

two acute porphyria with cutaneous sx

Answer 9

HCP and VP

Hereditary Coproporphyria + Variegate Porphyria

Question 10

Dx of acute porphyria with cutaneous sx?

Answer 10

Faecal porphyrins

Question 11

In which non-acute porphyria would you see liver disease?

Answer 11

PCT = Porphyria Cutanea Tarda

Question 12

Ferrochetalase deficiency –>

Answer 12

EPP = erythropoietic protoporphyria

Question 13

Porphyria Cutanea Tarda

• what is the main deficiency?

Answer 13

Uroporphyrinogen decarboxylase

Question 14

Skin involvement in non-acute porphyria?

Answer 14

Blistering/Pruritis/Oedema after sun exposure