Heme and Porphyrias Flashcards
AIP
Detection: ALA/PBG accumulation = urine red/brown
Enzyme Affected: PBGD (HMB) partially deficient
Etiology: 4Ms increase synthesis of hepatic cyto P450
Symptoms:
- No skin lesions
- At risk for primary liver cancer
- Neuro symptoms: abdominal pain, paralysis, psych disorders
Tx: Hematin/Hemin Glucose loading
PCT
Detection: UP/CP accumulation =urine/feces pink; UROD activity assay in RBC; UROD gene mutation analysis
Enzyme Affected: UROD deficienty
Etiology: Alcohol, hepatic iron overload, sunlight/photosensitivity, Hep B/C HIV, hydrochlorobenzene
Symptoms:
- 4th/5th decade life
- Skin – blullae, blisters, scars, milia, heliotropic face
- hypertrichosis
Tx: Avoid enviro exposures, sunlight (or use sunscreen), iron chelator, phlebotomy
EPP
Detection: Feces with porphyrin accumulation
Enzyme Affected: ferrochelatase
Etiology: Autosomal dominant
Symptoms:
- Early childhood presence
- Severe cutaneous photosensitivity
- chronic liver disease later
Treatment: Sunscreen, avoid sun ONLY
Pb Poisoning
Detection: ALA in urine; ZPP in blood; basophilic stippling in peripheral smear
Enzyme Affected: ALAD and ferrochelatase
Etiology: Environment
Symptoms:
Gingival, long bone lead line; arthralgia, abdominal cramps; peripheral neuropathy, encephalopathy, renal failure (more severe)
Treatment: Lead chelators?
Siderblastic Anemia
Detection: ring sideroblast in bone marror
Enzyme Affected:
- ALAS 2 (if genetic)
- ALAD/ferrochelatase (if Pb)
Etiology: ALAS2 (congential; erythroid, X-linked); Isoniazed for TB; ethanol; lead; pyrodoxine deficiency (diet)
Symptoms: Microcytic/hypochromic mature RBCs due to shortage of Hb; distrubed metabolism; ring sideroblasts
Treatment: Lead chelators?
