Succinylacetone, Blood Spot
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Second-tier newborn screening for tyrosinemia type 1 in blood spots with nonspecific elevations of tyrosine
Diagnosis of tyrosinemia type 1
Follow-up of patients with tyrosinemia type 1
Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request
Second-tier newborn screening for tyrosinemia, type 1 (Tyr 1) in blood spots with nonspecific elevations of tyrosine.
Diagnosis of Tyr 1.
Follow-up of patients with Tyr 1.
Tandem Mass Spectrometry (MS/MS)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Tyrosinemia Type I
Tyrosinemia Type I
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Container/Tube: Supplemental Newborn Screening Card (Supply T493)
Specimen Volume: 5 blood spots
1. Let blood dry on the filter paper at ambient temperature in a horizontal position for 3 hours.
2. Do not expose specimen to heat or direct sunlight.
3. Do not stack wet specimens.
4. Keep specimen dry.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Blood Spot: 1
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Whole blood||Ambient (preferred)|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Tyrosinemia type 1 (Tyr 1) is an autosomal recessive condition caused by fumarylacetoacetate hydrolase (FAH) deficiency. The incidence of Tyr 1 is approximately 1 in 100,000 live births, resulting in severe liver disease, hypophosphatemic rickets, renal tubular dysfunction, and neurologic crises. If left untreated, most patients die of liver failure in the first years of life. Over the past decade, treatment with 2-(2-nitro-4-tri-fluoromethylbenzoyl)-1,3 cyclohexanedione (NTBC) became available and is particularly effective when initiated in newborns.
While tyrosine can be determined by routine newborn screening, it is not a specific marker for Tyr I and often may be associated with common and benign transient tyrosinemia of the newborn. Succinylacetone (SUAC) is a specific marker for Tyr I, but is not detectable by routine newborn screening. This assay determines SUAC in newborn blood spots by tandem mass spectrometry. Additional follow-up testing may include confirmatory molecular analysis of the FAH gene.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided.
Normal: <5.0 mcM.
Elevations of succinylacetone (SUAC) above the reference range are indicative of Tyr I.
Patients with Tyr I who are treated with diet and/or NTBC (nitisinone) should have declining or normal values of SUAC.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Normal levels may be seen in affected individuals undergoing treatment.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
Mitchell GA, Grompe M, Lambert M, Tanguay RM: Hypertyrosinemia. In The Metabolic and Molecular Bases of Inherited Disease. Eighth edition. Edited by CR Scriver, AL Beaudet, WS Sly, et al. New York, McGraw-Hill Book Company, 2001, pp 1777-1805
Method Description Describes how the test is performed and provides a method-specific reference
A 3/16-inch disk is punched out of the blood spot onto 96-well plate. Then, the amino acids and acylcarnitines are extracted by the addition of methanol and known concentrations of isotopically labeled amino acids and acylcarnitines as internal standards. The extract is moved to another 96-well plate, dried under a stream of nitrogen, and derivatized by the addition of n-butanol hydrochloric acid. In a parallel process, succinylacetone is extracted from the residual blood spot, derivatized with an acidic hydrazine solution, evaporated and combined with the amino acid and acylcarnitine extract amino acids and acylcarnitines are measured as their butyl esters with the hydrazone derivative of succinylacetone by electrospray MS/MS. The concentrations of the analytes are established by computerized comparison of ion intensities of these analytes to that of the respective internal standards.(Chace DH, Naylor EW: Expansion of newborn screening programs using automated tandem mass spectrometry. MRDD Res Rev 1999;5:150-154; Turgeon C, Magera MJ, Allard P, et al: Combined newborn screening for succinylacetone, amino acids, and acylcarnitines in dried blood spots. Clin Chem 2008 Apr;54(4):657-664)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 11 a.m. and 2 p.m., Saturday; 2 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
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 Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|22711||Reason For Referral||42349-1|