Specialized AA

Question 1

What two enzymes are inhibited by lead in the heme biosynthesis pathway?

Answer 1

ALA DEHYDROTASE AND FERROCHELATASE (mito)

Question 2

What are porphyrias due to?

Answer 2

Blockage in heme pathway

Question 3

What is acute porphyria?

Answer 3

Acute abdominal pain and neuropsychiatric abnormalities

Accumulation of ALA and PBG

Question 4

Cutaneous porphyria?

Answer 4

Photo sensitivity (skin lesions)
Accumulation of porphyrins

Question 5

Kernicterus encephalopathy

Answer 5

Unconjugated bilirubin can cross the BBB and enter into CNS bc of its hydrophobic property

Question 6

Gilbert syndrome

Answer 6

Hepatic jaundice

• mutation in gene coding for UDP-glucuronyl transferase
• harmless
• plasma unconjugated bilirubin increased

Question 7

Crigler-Najjar Syndrome Type I

Answer 7

• AR
• fatal within first 15 months
• unconjugated bilirubin may exceed 20 mg/dl–may lead to kernicterus
• phenobarbital has no effect
• def of UDP GLUC TRANSFERASE

Question 8

CNS TYPE II

Answer 8

• def of UDP GLUC TRANSFERASE, some activity is retained
• less severe than type I
• unconjugated bilirubin increase in serum
• may respond to phenobarbital

Question 9

Dubin-Johnson syndrome

Answer 9

Mutation in gene encoding the protein involved in secretion of conjugated bilirubin

• conjugated bilirubin increase in plasma
• bilirubin in urine

Question 10

Prehepatic/hemolytic jaundice

Answer 10

Unconjugated bilirubin increase in plasma

• more conjugated bilirubin is excreted into bile which leads to increased amount of urobilinogen entering enterohepatic circulation
• urinary urobilinogen increased

Question 11

Synthesis of this enzyme is increased by phenobarbital

Answer 11

Glucuronyl transferase