Aminoacidopathy

Question 1

Main amino acid affected: Phenylketonuria

Answer 1

Phenylalanine

Question 2

Defective enzyme: Phenylketonuria

Answer 2

phenylalanine hydroxylase

Question 3

Toxic product build-up: Phenylketonuria

Answer 3

Phenylalanine & its toxic metabolites- phenylpyruvate

Tyrosine is low

Question 4

Associated Symptoms: Phenylketonuria

Answer 4

• progressive development delay
  
  • microcephaly, mental retardation, seizures, hyperactivity
• Musty odor (from phenylacetate)
• Hypopigmentation (tyrosine is not converted to melanin)

Question 5

Main Amino Acid affected: Tyrosinemia- Type 1

Answer 5

Tyrosine

Question 6

Defective enzyme/transporter: Tyrosinemia- Type 1

Answer 6

fumarylacetoacetate hydrolase (5)

Question 7

Toxic product build up: Tyrosinemia- Type 1

Answer 7

• Succinylacetoacetate
• Succinylacetone (liver & kidney toxin)

Question 8

Associated Symptom: Tyrosinemia- Type 1

Answer 8

• “cabbage-like” odor
• failure to thrive
• rickets
• liver & kidney failure if untreated

Question 9

Main amino acid affected: Alkaptonuria

Answer 9

Tyrosine

Question 10

Defective enzyme/transporter: Alkaptonuria

Answer 10

homogentisic acid oxidse (3)

Question 11

Toxic product built-up: Alkaptonuria

Answer 11

Homogentisic acid (HGA)

Question 12

Associated Symptoms: Alkaptonuria

Answer 12

• patient’s urine turns brownish-black when exposed to air due to darkening of HGA by oxidation
• Ochronosis: blue-black HGA pigment deposited in skin & sclera
• Arthritis of weight bearing joints: HGA pigment deposited in connective tissue and cartilage

Question 13

Main amino acid affected: Homocysteinuria

Answer 13

Methionine & cysteine

Question 14

Defective enzyme: Homocysteinuria

Answer 14

cystathionine synthase

Question 15

Toxic product built-up: Homocysteinuria

Answer 15

Homocysteine & methionine

Question 16

Associated symptoms: Homocysteinuria

Answer 16

thrombosis

Question 17

Main amino acids affected: Maple Syrup urine disease

Answer 17

Leucine, Isoleucine, Valine

Question 18

Defective Enzyme: Maple Syrup urine disease

Answer 18

“branched-chain alpha keto acid decarboxylase/ dehydrogenase complex”

Question 19

Toxic product built-up: maple syrup urine disease

Answer 19

byproducts of Leu, Ile, and Val (branch chain keto acids)

accumulate in blood, urine, and CSF

Question 20

Associated symptoms: Maple Syrup urine disease

Answer 20

• burned sugar or maple syrup odor of urine, breath & skin
• Ketoacidosis
• hypoglycemia

Question 21

Toxic product built up: Propionic acidemia

Answer 21

Propional Co-A

Question 22

Associated symptoms: Propionic acidemia

Answer 22

• metabolic acidosis
• ketonuria
• hypoglycemia
• hyperammonia

Question 23

Toxic product built-up: Methylmalonic acidemia

Answer 23

Methylmalonyl Co-A

Question 24

Associated symptoms: Methylmalonic acidemia

Answer 24

• metabolic acidosis
• ketonuria
• hypoglycemia
• hyperammonia

Question 25

Toxic product built-up: Isovaleric acidemia

Answer 25

Isovaleryl Co-A

Question 26

Associated symptoms: Isovaleric acidemia

Answer 26

“sweaty feet odor”

Question 27

Main Amino acid affected: Citrullinemia Type 1

Answer 27

Aspartate

Question 28

Defective enzyme: Citrullinemia Type 1

Answer 28

mutation causes arginine-succinate synthase deficiency

Question 29

Toxic product built-up: Citrullinemia Type 1

Answer 29

Citrulline

Question 30

Associated symptoms: Citrullinemia Type 1

Answer 30

* Neonatal * hyperammonia

Question 31

Main amino acid affected: Citrullinemia Type 2

Answer 31

Aspartate

Question 32

Defective transporter: Citrullinemia Type 2

Answer 32

defect in transport protein citrin

Question 33

Toxic product built-up: Citrullinemia Type 2

Answer 33

Citrulline

Question 34

Associated Symptoms: Citrullinemia Type 2

Answer 34

* adult onset * hyperammonia

Question 35

Main amino acid affected: Argininosuccinic aciduria

Answer 35

Argine

Question 36

Defective enzyme: Argininosuccinic aciduria

Answer 36

Argininesuccinate lyase

Question 37

Toxic product built-up: Argininosuccinic aciduria

Answer 37

Argininosuccinate