Porphyrias Flashcards

1
Q

three porphyria disorders

A
  1. acute intermittent porphyria
  2. Porphyria Cutanea Tarda
  3. Lead Poisoning
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2
Q

acute intermittent porphyria has defect in which enzyme and requires the induction of which enzyme

A

PBG deaminase; ALAS

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3
Q

porphyrias

A

are disorders with deficiencies with enzymes that help make heme; cause buildup of porphyrins (metabolites); usually inherited

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4
Q

PBG deaminase completes which reaction

A

occurs in the cytoplasm

PBG (porphobilinogen) –> HMB (hydroxymethylbilane)

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5
Q

porphyria can lead to

A

facial hair and red glowing teeth

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6
Q

What is the committed enzyme for formation fo heme?

A

ALAS

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7
Q

What induces ALAS activity?

A
  1. hepatic depletion of heme
  2. metabolic stress
  3. drugs
  4. hormones
  5. smoke
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8
Q

clinical presentation of AIP ?

A
  1. increased catecholamines which can increase heart rate and lead to hypertension
  2. CNS- seizures
  3. GI pain without inflammation
  4. insomnia
  5. acute and intermittent
  6. SIADH- hyponatremia (low sodium)
  7. red or dark urine when exposed to sunlight
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9
Q

ALAS reaction

A

succinyl CoA + glycine –> ALA

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10
Q

acute intermittent porphyria has what type of inheritance

A

autosomal dominant

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11
Q

acute intermittent porphyria is low or high penetrance

A

low

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12
Q

laboratory findings

A
  1. increased ALA and PBG

2. decreased activity of PBG deaminase

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13
Q

treatment

A
  1. stop induction so medication, smoking, drug, metabolic stress
  2. increase carbohydrates
  3. glucose 10 %
  4. hematin
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14
Q

hematin inhibits which enzyme

A

ALAS

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15
Q

prolonged attacks of AIP can lead to which peripheral neuropathy motor symptoms

A
  1. bulbar paralysis
  2. respiratory impairment
  3. death
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16
Q

exacerbating factors of AIP?

A
  1. decreased carb diet
  2. drugs
  3. hormones
  4. metabolic stresses- infections, surgery, psychological stress
  5. cigarette smoke
17
Q

Porphyria Cutanea Tarda is caused by

A

deficiency of UROD (uroporphyrinogen decarboxylase)

18
Q

UROD uroporphyrinogen decarboxylase reaction

A

uroporphyrinogen III –> coprophyrinogen III

19
Q

what leads to reduced activity of the enzyme

A

iron overload

20
Q

______ is correlated with clinical expression of this disease

A

hepatic iron levels

21
Q

three associated disorders

A
  1. alcoholism
  2. hemochromatosis
  3. hep C
22
Q

when uroporphyrinogen is made in the _____ it is deposited in the _______ as a metabolite and causes ____

A

liver; skin; blisters and rash

23
Q

patients with PCT are at increased risk for

A

cirrhosis and heptacellular carcinoma

24
Q

diagnosis

A

clinical

- normal levels of ALA and PBG

25
Q

PCT treatment

A
  • remove all offending agents (alcohol, smoke and estrogen)
  • sunscreen and sun exposure protection
  • phlebotomy
26
Q

lead poisoning is microcytic or macrocytic

A

microcytic

27
Q

lead poisoning in children is usually via ______ and in adults via ______

A

ingestion; inhalation

28
Q

forms of lead

A
  • moonshine
  • makeup
  • gas
  • paint
  • water
29
Q

clinical signs of lead poisoning

A
  • lead line
  • decreased libido
  • muscle joint pain
  • wrist and foot drop
  • microcytic anemia
  • GO effects- crampy abdominal pain (lead colic) constipation
30
Q

diagnosis

A
  • blood test

- venous for children

31
Q

treatment

A
  • reduce lead exposure

- chelation therapy

32
Q

lead poisoning level for children ___

lead poising for adults

A

5
10
should be 0

33
Q

once in the body 99% of lead is bound to

A

RBS

34
Q

lead biochemical effects

A

inhibits ALAS and ferrochelatase

35
Q

ferrochelatase

A

last enzyme that formation of heme adds the Fe

36
Q

blood smear for lead poisoning shows

A

basophilic stippling

37
Q

lead exposure chronic effects

A
  1. hypertension
  2. neuropsychiatric effects
  3. mortality
  4. reproductive effects
  5. lead neuropathy
  6. saturnine gout
38
Q

chelation therapy

A

should not be used unless exposure has been definitively curtailed since in the presence of continuous exposure it can cause increased absorption

39
Q

atkins diet

A

low carb diet that can induce ALAS