Aminoacidopathy Flashcards
Main amino acid affected: Phenylketonuria
Phenylalanine
Defective enzyme: Phenylketonuria
phenylalanine hydroxylase
Toxic product build-up: Phenylketonuria
Phenylalanine & its toxic metabolites- phenylpyruvate
Tyrosine is low
Associated Symptoms: Phenylketonuria
- progressive development delay
- microcephaly, mental retardation, seizures, hyperactivity
- Musty odor (from phenylacetate)
- Hypopigmentation (tyrosine is not converted to melanin)
Main Amino Acid affected: Tyrosinemia- Type 1
Tyrosine
Defective enzyme/transporter: Tyrosinemia- Type 1
fumarylacetoacetate hydrolase (5)
Toxic product build up: Tyrosinemia- Type 1
- Succinylacetoacetate
- Succinylacetone (liver & kidney toxin)
Associated Symptom: Tyrosinemia- Type 1
- “cabbage-like” odor
- failure to thrive
- rickets
- liver & kidney failure if untreated
Main amino acid affected: Alkaptonuria
Tyrosine
Defective enzyme/transporter: Alkaptonuria
homogentisic acid oxidse (3)
Toxic product built-up: Alkaptonuria
Homogentisic acid (HGA)
Associated Symptoms: Alkaptonuria
- 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
Main amino acid affected: Homocysteinuria
Methionine & cysteine
Defective enzyme: Homocysteinuria
cystathionine synthase
Toxic product built-up: Homocysteinuria
Homocysteine & methionine
Associated symptoms: Homocysteinuria
thrombosis
Main amino acids affected: Maple Syrup urine disease
Leucine, Isoleucine, Valine
Defective Enzyme: Maple Syrup urine disease
“branched-chain alpha keto acid decarboxylase/ dehydrogenase complex”
Toxic product built-up: maple syrup urine disease
byproducts of Leu, Ile, and Val (branch chain keto acids)
accumulate in blood, urine, and CSF
Associated symptoms: Maple Syrup urine disease
- burned sugar or maple syrup odor of urine, breath & skin
- Ketoacidosis
- hypoglycemia
Toxic product built up: Propionic acidemia
Propional Co-A
Associated symptoms: Propionic acidemia
- metabolic acidosis
- ketonuria
- hypoglycemia
- hyperammonia
Toxic product built-up: Methylmalonic acidemia
Methylmalonyl Co-A
Associated symptoms: Methylmalonic acidemia
- metabolic acidosis
- ketonuria
- hypoglycemia
- hyperammonia
Toxic product built-up: Isovaleric acidemia
Isovaleryl Co-A
Associated symptoms: Isovaleric acidemia
“sweaty feet odor”
Main Amino acid affected: Citrullinemia Type 1
Aspartate
Defective enzyme: Citrullinemia Type 1
mutation causes arginine-succinate synthase deficiency
Toxic product built-up: Citrullinemia Type 1
Citrulline
Associated symptoms: Citrullinemia Type 1
- Neonatal
- hyperammonia
Main amino acid affected: Citrullinemia Type 2
Aspartate
Defective transporter: Citrullinemia Type 2
defect in transport protein citrin
Toxic product built-up: Citrullinemia Type 2
Citrulline
Associated Symptoms: Citrullinemia Type 2
- adult onset
- hyperammonia
Main amino acid affected: Argininosuccinic aciduria
Argine
Defective enzyme: Argininosuccinic aciduria
Argininesuccinate lyase
Toxic product built-up: Argininosuccinic aciduria
Argininosuccinate