Hereditary Tyrosinemia

Question 1

Fumarylacetoacetate (FAA) gets turned into fumarate and acetoacetate by what enzyme?

Answer 1

Fumarylacetoacetate hydrolase

FAA hydrolase

Question 2

If an individual has decreased or absent FAA hydrolase what type of tyrosinemia is this?

Answer 2

Hereditary tyrosinemia type 1

Question 3

Name 3 clinical features of individuals with hereditary tyrosinemia type 1

Answer 3

1. Severe liver disease (hepatic crisis)
2. Fanconi syndrome in the kidney
3. Peripheral nerve disease

Question 4

How old are individuals when they present with Hereditary Tyrosinemia type 1?

Answer 4

Usually infants 2-6months of age

Question 5

What metabolite will be elevated in serum and urine in individuals with hereditary tyrosinemia type 1?

Answer 5

Succinylacetone

Question 6

How do you tx individuals with hereditary tyrosinemia type 1

Answer 6

low Phenylalanine and Tyrosine diet.

Question 7

What drug can slow progression of hereditary tyrosinemia type 1?

How does it work?

Answer 7

nitisinone; it inhibits tyrosine degredation

However, individuals usually already have liver damage by the time this is started.

Question 8

What is tyrosine a precursor for?

Answer 8

dopamine, NE, epinephrine, melanin and thyroxine

Question 9

What enzyme is responsible for converting tyrosine into 4-hydroxyphenylpyruvate (4HPP)

Answer 9

Tyrosine aminotransferase

Question 10

What enzyme is affected in individuals with Type 2 Hereditary Tyrosinemia

Answer 10

Tyrosine aminotransferase

Question 11

How is Type 2 Hereditary Tyrosinemia inherited?

Answer 11

Autosomal recessive

Question 12

Name 3 features of Type 2 hereditary tyrosinemia

Answer 12

1. Palmar/plantar hyperkeratosis
2. Herpetiform corneal ulcers
3. Intellectual disability

Question 13

Name 3 complications of acquired Tyrosinemia

Answer 13

1. Hepatocellular dysfunction (severe)
2. Scurvy
3. Hyperthyroidism