Blood Spot Disorders: Metabolic Disorders, Amino Acid Profile

Argininemia (ARG), aka arginase deficiency

FINDING
The amino acid arginine is elevated.

OTHER ASSOCIATED DISORDERS
None

CAUSE
An enzyme needed to break down protein from food and remove the waste product ammonia from the body is not working correctly.

EARLY SIGNS
There are usually no symptoms in the newborn period. If left untreated, the disorder can cause lack of energy, poor feeding and growth, muscle stiffness, intellectual disabilities, and seizures.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Borderline result (PDF)
For Family - Positive result: ARG (PDF)
For Provider - Positive result: ARG (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Argininosuccinic acidemia (ASA), aka argininosuccinate lyase (AKA) deficiency

FINDING
The amino acid argininosuccinic acid is at an elevated level.

OTHER ASSOCIATED DISORDERS
None

CAUSE
An enzyme needed to remove a waste product called ammonia from the body is not working correctly.

EARLY SIGNS
Symptoms can begin in the newborn period. If left untreated, the disorder can cause lack of energy, poor feeding, unusual body movements, seizures, brain damage, and coma.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Borderline result (PDF)
For Family - Positive result: ASA (PDF)
For Provider - Positive result: ASA (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Biopterin defect in cofactor biosynthesis (BIOPT-BS)

FINDING
The amino acid phenylalanine is at an elevated level.

OTHER ASSOCIATED DISORDERS
Phenylketonuria (PKU)
Hyperphenylalaninemia (H-PHE)
Biopterin defect in cofactor regeneration (BIOPT-REG)

CAUSE
A critical substance that helps an enzyme break down protein from food cannot be made.

EARLY SIGNS
If untreated, the disorder can cause lack of energy, poor feeding, muscle weakness, developmental delays, behavioral problems, and seizures.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Borderline result (PDF)
For Family - Positive result: BIOPT-BS (PDF)
For Provider - Positive result: BIOPT-BS (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Biopterin defect in cofactor regeneration (BIOPT-REG)

FINDING
The amino acid phenylalanine is at an elevated level.

OTHER ASSOCIATED DISORDERS
Phenylketonuria (PKU)
Hyperphenylalaninemia (H-PHE)
Biopterin defect in cofactor biosynthesis (BIOPT-BS)

CAUSE
A key substance that helps an enzyme break down protein from food cannot be recycled and reused.

EARLY SIGNS
If untreated, the disorder can cause lack of energy, poor feeding, muscle weakness, developmental delays, behavioral problems, and seizures.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Borderline result (PDF)
For Family - Positive result: BIOPT-REG (PDF)
For Provider - Positive result: BIOPT-REG (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Citrullinemia type 1 (CIT-I)

FINDING
The amino acid citrulline is at an elevated level.

OTHER ASSOCIATED DISORDERS
Citrullinemia type 2 (CIT-II)

CAUSE
An enzyme needed to remove ammonia from the body is not working correctly. Ammonia is a waste product created when the body breaks down protein from food.

EARLY SIGNS
Symptoms can begin in the newborn period. If left untreated, the disorder can cause lack of energy, poor feeding, seizures, brain damage, and coma.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Positive result: CIT-I (PDF)
For Provider - Positive result: CIT-I (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Citrullinemia type 2 (CIT-II)

FINDING
The amino acid citrulline is at an elevated level.

OTHER ASSOCIATED DISORDERS
Citrullinemia type 1 (CIT-I)

CAUSE
An enzyme needed to break down carbohydrates from food and remove the waste product ammonia from the body is not working correctly.

EARLY SIGNS
Symptoms can begin in infancy. If untreated, children can develop jaundice (yellowing of skin and eyes), delayed growth, and low blood sugar.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Positive result: CIT-II (PDF)
For Provider - Positive result: CIT-II (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Homocystinuria (HCY), aka cystathionine beta-synthase (CBS) deficiency

FINDING
The amino acid methionine is at an elevated level. Additional screening shows elevated total homocysteine.

OTHER ASSOCIATED DISORDERS
Hypermethioninemia (MET)

CAUSE
An enzyme needed to break down protein from food is not working correctly.

EARLY SIGNS
Symptoms typically begin after a year of age. If untreated, children can develop eye problems, blood clots, bone abnormalities, intellectual disabilities, and behavioral problems.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)
2nd tier: liquid chromatography-tandem mass spectrometry (LC-MS/MS) by Mayo Clinic Laboratories

FACT SHEETS
For Family - Positive result: HCY (PDF)
For Provider - Positive result: HCY (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Hypermethioninemia (MET), aka glycine N-methyltransferase (GNMT) deficiency

FINDING
The amino acid methionine is elevated.

OTHER ASSOCIATED DISORDERS
Homocystinuria (HCY)

CAUSE
An enzyme needed to break down protein from food is not working correctly.

EARLY SIGNS
Many children never develop symptoms. If untreated, some children may develop muscle weakness, lack of energy, a “cabbage-like”’ smell, and intellectual disabilities.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Positive result: MET (PDF)
For Provider - Positive result: MET (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Hyperphenylalaninemia (H-PHE), aka PKU variant

FINDING
The amino acid phenylalanine is elevated.

OTHER ASSOCIATED DISORDERS
Phenylketonuria (PKU)
Biopterin defect in cofactor biosynthesis (BIOPT-BS)
Biopterin defect in cofactor regeneration (BIOPT-REG)

CAUSE
An enzyme needed to break down protein from food is not working correctly.

EARLY SIGNS
Most children never develop symptoms. If untreated, some children have a small risk of brain damage.

TREATMENT
Treatment is not always needed. If treatment is recommended, it would consist of a special diet.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Borderline result (PDF)
For Family - Positive result: H-PHE (PDF)
For Provider - Positive result: H-PHE (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Maple syrup urine disease (MSUD), aka branched-chain alpha-keto acid dehydrogenase (BCKD) deficiency

FINDING
The amino acids leucine, isoleucine, and other branched-chain amino acids are at elevated levels. Additional screening shows elevated alloisoleucine.

OTHER ASSOCIATED DISORDERS
None

CAUSE
An enzyme needed to break down protein from food is not working correctly.

EARLY SIGNS
There are multiple forms of MSUD. The most common and severe form begins in the newborn period. Symptoms include poor feeding, vomiting, lack of energy, urine that smells sweet like maple syrup, and a high-pitched cry. If untreated, children can develop intellectual disabilities, seizures, brain swelling, coma, and a shortened lifespan.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)
2nd tier: liquid chromatography-tandem mass spectrometry (LC-MS/MS) stable isotope dilution analysis by Mayo Clinic Laboratories

FACT SHEETS
For Family - Positive result: MSUD (PDF)
For Provider - Positive result: MSUD (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Phenylketonuria (PKU), aka phenylalanine hydroxylase (PAH) deficiency

FINDING
The amino acid phenylalanine is elevated.

OTHER ASSOCIATED DISORDERS
Hyperphenylalaninemia (H-PHE)
Biopterin defect in cofactor biosynthesis (BIOPT-BS)
Biopterin defect in cofactor regeneration (BIOPT-REG)

CAUSE
An enzyme needed to break down protein from food is not working correctly.

EARLY SIGNS
Symptoms begin in infancy and include irritability, dry skin (eczema), and growth problems. If untreated, the disorder can cause intellectual disabilities and seizures.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Borderline result (PDF)
For Family - Positive result: PKU (PDF)
For Provider - Positive result: PKU (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Proximal urea cycle defect (UCD)

FINDING
The amino acid citrulline was either low or absent.

OTHER ASSOCIATED DISORDERS
None

CAUSE
An enzyme needed to remove the waste product ammonia from the body is not working correctly.

EARLY SIGNS
Symptoms can begin within the first few days of life and include lack of energy, poor feeding and growth, and seizures. If untreated, children can go into a coma and die.

TREATMENT
Consists of a special diet and medications. Sometimes dialysis, a procedure that removes toxins from the blood, is needed. In severe cases, a liver transplant is considered.

DISORDER GROUP
Metabolic

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Positive result (PDF)
For Provider - Positive result (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Tyrosinemia type 1 (TYR-I), aka hepatorenal tyrosinemia

FINDING
The metabolite succinylacetone is elevated.

OTHER ASSOCIATED DISORDERS
None

CAUSE
An enzyme needed to break down protein from food is not working correctly.

EARLY SIGNS
Symptoms begin in infancy and include diarrhea, vomiting, lack of energy, “cabbage-like” smell, jaundice (yellowing skin and eyes), and nosebleeds. If untreated, TYR-I can cause kidney and liver problems, trouble breathing, seizures, and coma.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Positive result: TYR-I (PDF)
For Provider - Positive result: TYR-I (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Tyrosinemia type 2 (TYR-II), aka oculocutaneous tyrosinemia

FINDING
The amino acid tyrosine is at an elevated level. Its metabolite, succinylacetone, is within normal limits.

OTHER ASSOCIATED DISORDERS
Tyrosinemia type 3 (TYR-III)

CAUSE
An enzyme needed to break down protein from food is not working correctly.

EARLY SIGNS
Symptoms begin in infancy and include teary eyes, sensitivity to light, eye redness, skin problems, and poor muscle coordination.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Borderline result (PDF)
For Family - Positive result: TYR-II (PDF)
For Provider - Positive result: TYR-II (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)

Tyrosinemia type 3 (TYR-III)

FINDING
The amino acid tyrosine is elevated. Its metabolite, succinylacetone, is within normal limits.

OTHER ASSOCIATED DISORDERS
Tyrosinemia type 2 (TYR-II)

CAUSE
An enzyme needed to break down protein from food is not working correctly.

EARLY SIGNS
With not many cases reported amongst millions of children screened, it is difficult to know how the disorder affects children. In the reported cases, symptoms included poor muscle coordination and seizures.

TREATMENT
Consists of a special diet and medications.

DISORDER GROUP
Metabolic (amino acid disorder)

SCREENING METHOD
Tandem mass spectrometry (MS/MS)

FACT SHEETS
For Family - Borderline result (PDF)
For Family - Positive result: TYR-III (PDF)
For Provider - Positive result: TYR-III (PDF)

SPECIALIST CONTACT LIST
Metabolic specialist contact list (PDF)