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Test ID: TYRBS Tyrosinemia Follow Up Panel, Blood Spot


Necessary Information


Patient's age and reason for referral are required.



Specimen Required


Submit only 1 of the following specimen types:

 

Preferred:

Specimen Type: Blood spot

Supplies: Card-Blood Spot Collection (Filter Paper) (T493)

Container/Tube:

Preferred: Blood Spot Collection Card

Acceptable: Whatman Protein Saver 903 Paper, Ahlstrom 226 filter paper, Munktell filter paper, or blood collected in tubes containing heparin, ACD or EDTA and dried on filter paper.

Specimen Volume: 2 Blood spots

Collection Instructions:

1. Let blood dry on filter paper at room temperature in a horizontal position for 3 or more hours.

2. At least 2 spots should be complete (ie, unpunched).

3. Do not expose specimen to heat or direct sunlight.

4. Do not stack wet specimens.

5. Keep specimen dry.

Specimen Stability Information: Ambient (preferred) 90 days/Refrigerated 90days/Frozen 90 days

Additional Information:

1. For collection instructions, see Blood Spot Collection Instructions in Special Instructions.

2. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777) in Special Instructions.

3. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800) in Special Instructions.

 

Acceptable

Specimen Type: Whole Blood

Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: Green top (sodium or lithium heparin) and yellow top (ACD)

Specimen Volume: 2 mL

Collection Instructions: Send specimen in original tube.

Specimen Stability Information: Refrigerate (preferred) 4 days/Ambient 4 days


Useful For

Monitoring of individuals with tyrosinemia type I (HT-1)

 

Diagnosis of HT-1 along with urine organic acids (OAU), liver function tests, alpha-fetoprotein, and molecular genetic analysis of the fumarylacetoacetate hydrolase (FAH) gene

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Tyrosinemia Follow Up Panel, BS

Specimen Type

Whole blood

Specimen Minimum Volume

Blood Spots: 1
Whole Blood: 0.5 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole blood Varies

Clinical Information

Tyrosinemia type 1 (Hepatorenal Tyrosinemia, HT-1) is an autosomal recessive condition caused by a deficiency of the enzyme fumarylacetoacetate hydrolase (FAH). HT-1 primarily affects the liver, kidneys, and peripheral nerves causing severe liver disease, renal tubular dysfunction, and neurologic crises. If left untreated, most patients die of liver failure in the first years of life, and all are at risk of developing hepatocellular carcinoma (HCC). The incidence of HT-1 is approximately 1 in 100,000 live births.

 

Affected individuals can show a partial response to dietary restriction of phenylalanine and tyrosine, but dietary treatment in conjunction with the administration of 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3 cyclohexanedione (NTBC; nitisinone), an inhibitor of the proximal tyrosinemia pathway, is very effective when initiated in newborns. Outcome data are promising and to date, newborn patients treated with NTBC have not developed acute liver disease, neurologic crises, or HCC.

 

According to treatment guidelines established in 2017, monitoring of blood NTBC concentration and succinylacetone (SUAC) levels along with measuring the dietary intake of amino acids, including tyrosine and phenylalanine are part of an individualized surveillance plan for patients with HT-1.(1) Monthly analysis of SUAC, NTBC concentration, and amino acids is suggested for the first year of life with the same compounds being monitored every three months to age five and every six months thereafter. The analytes encompassed in this assay satisfy the recommendations for diagnosis and monitoring of HT-1.

Reference Values

TYROSINE: <4 weeks 40.0-280.0 nmol/mL

≥4 weeks 25.0-150.0 nmol/mL

PHENYLALANINE:

27.0-107.0 nmol/mL

METHIONINE:

11.0-45.0 nmol/mL

SUCCINYLACETONE:

<1.00 nmol/mL

NITISINONE:

<0.7 nmol/mL

Interpretation

Quantitative results with reference values are reported without added interpretation. When applicable, reports of abnormal results may contain an interpretation based on available clinical information.

Clinical Reference

1. Chinsky JM, Singh R, Ficiciolglu C, et. al: Diagnosis and treatment of tyrosinemia type I: a US and Canadian consensus group review and recommendations. Genet Med 2017. Dec 19(12) pp 1-16. doi: 10.1038/gim.2017.101

2. Mitchell GA, Grompe M, Lambert M, et al: Mitchell G.A., Grompe M, Lambert M, Tanguay R.M. Mitchell, Grant A., et al.Hypertyrosinemia. In The Online Metabolic and Molecular Bases of Inherited Disease. Edited by D Valle, AL Beaudet, B Vogelstein, et al.  McGraw-Hill; 2014. Accessed February 26, 2019. http://ommbid.mhmedical.com/content.aspx?bookid=971&sectionid=62673883

3. Blackburn PR, Hickey RD, Nace RA, et al: Silent tyrosinemia type I without elevated tyrosine or succinylacetone associated with liver cirrhosis and hepatocellular carcinoma. Hum Mutat. 2016;37(10):1097–1105. doi:10.1002/humu.23047

Day(s) and Time(s) Performed

Monday through Friday, 9 a.m.

Analytic Time

3 days

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

84510

84030

82131

82542

80299

LOINC Code Information

Test ID Test Order Name Order LOINC Value
TYRBS Tyrosinemia Follow Up Panel, BS 94573-3

 

Result ID Test Result Name Result LOINC Value
607553 Tyrosine 35571-9
607554 Phenylalanine 29573-3
607555 Methionine 47700-0
607556 Succinylacetone 53231-7
607557 Nitisinone 85098-2
BG722 Reason for Referral 42349-1
607552 Reviewed By 18771-6
Mayo Clinic Laboratories | Genetics and Pharmacogenomics Catalog Additional Information:

mml-biochemical