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Mayo Test ID FFTEN Tetrahydrobiopterin and Neopterin Profile (BH4, N)

Reporting Name

Tetrahydrobiopterin/Neopterin

Performing Laboratory

Medical Neurogenetics, LLC

Specimen Type

CSF


Specimen Required


Medical Neurogenetics collection kit (T657) required.

Each collection kit contains 5 microcentrifuge tubes.

 

COLLECTION PROTOCOL:

1)     CSF should be collected from the first drop into the tubes in the  numbered order. Fill each tube to the marked line with the required volumes

Tube 1: 0.5 mL

Tube 2: 1.0 mL

Tube 3: 1.0 mL (contains antioxidants necessary to protect the sample integrity)

Tube 4: 1.0 mL

Tube 5: 1.0 mL

-       If sample's not blood contaminated, the tubes should be placed on dry ice at bedside

-       If sample's are blood contaminated, the tubes should immediately be centrifuged (prior to freezing) and the clear CSF transferred to new similarly labeled tubes, then frozen

-       Store samples at -80 until they can be shipped

2)     Complete Medical Neurogenetics, LLC request form. Include test required, sample date and date of birth.  

3)     Label tubes with patient name and ID number, leaving the tube number viewable.

4)     Place samples inside a specimen transport bag and the Medical Neurogenetics, LLC request form inside the pouch of the transport bag.

5)     Ship samples frozen on dry ice.


Specimen Stability Information

Specimen Type Temperature Time Special Container
CSF Frozen CSF KIT

Reference Values

Tetrahydrobiopterin/Neopterin Profile

 

Age

BH4

Neop

(years)

(nmol/L)

(nmol/L)

0 – 0.2

40 – 105

7 – 65

0.2 – 0.5

23 – 98

7 – 65

0.5 – 2.0

18 – 58

7 – 65

2.0 – 5.0

18 – 50

7 – 65

5.0 – 10

9 – 40

7 – 40

10 – 15

9 – 32

8 – 33

Adults

10 – 30

8 - 28

 

Note: If test results are consistent with the clinical presentation, please call our laboratory to discuss the case and/or submit a second sample for confirmatory testing.

 

An important consideration for false positive for false negative results is the improper labeling of the patient sample.

Day(s) Performed

Monday through Friday

CPT Code Information

82542

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FFTEN Tetrahydrobiopterin/Neopterin 80168-8

 

Result ID Test Result Name Result LOINC Value
Z2234 Neopterin 34146-1
Z2235 Tetrahydrobiopterin Not Provided
Z2236 Interpretation 59462-2

Test Classification

This test was developed and its performance characteristics determined by Medical Neurogenetics, LCC. It has not been cleared or approved by the U.S. FDA.

Report Available

10 to 18 days

Reject Due To

Specimens other than CSF in special collection kit (T657)
Anticoagulants other than NA
Hemolysis NA
Lipemia NA
Icteric NA

Method Name

HPLC/Electrochemistry/Fluorescence

Clinical Information

CSF Neopterin/Tetrahydrobiopterin (NC03) is useful for diagnosis of certain disorders of neurotransmitter metabolism. This testing may also be used for assessment of Variants of Uncertain Significance (VUS) identified during genetic testing (e.g. Next Generation Sequencing or Capillary Sequencing Testing). CLINICAL Tetrahydrobiopterin (BH4) serves as a cofactor for the hydroxylation of phenylalanine and in the biosynthesis of biogenic amines. Deficiency of BH4 may occur as a result of mutations causing a reduction in one of the three biosynthetic enzymes, guanosine triphosphate cyclohydrolase, 6-pyruvoyl-tetrahydropterin synthase, sepiapterin reductase, or the two regenerating enzymes, pterin-4-carbinolamine dehydratase, and dihydropteridine reductase. Defects in BH4 metabolism can result in hyperphenylalaninemia and deficiency of the neurotransmitters dopamine and serotonin. Changes in CSF neopterin may also occur in deficiency of the BH4 synthesis pathway. Disorders of BH4 metabolism are characterized by a wide range of symptoms that may include developmental delay, mental disability, behavioral disturbances, dystonia, Parkinsonian symptoms, gait disturbances, speech delay, psychomotor retardation and ptosis.