Test Catalog

Test Id : TALDO

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Polyols, Quantitative, Urine

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Overview

Test Catalog

Useful For
Suggests clinical disorders or settings where the test may be helpful

Diagnosing deficiencies of transaldolase, transketolase, sedoheptulose, or ribose-5-phosphate isomerase

Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request

This is a screening test for disorders of the pentose phosphate pathway such as transaldolase deficiency, transketolase deficiency, sedoheptulokinase deficiency, or ribose-5-phosphate isomerase deficiency.

Highlights

Transaldolase (TALDO) deficiency, transketolase deficiency, and ribose-5-phosphate (RPI) deficiency are 3 recently described multisystem disorders of the pentose phosphate pathway.

 

Correlation to disease manifestations is unclear in sedoheptulokinase deficiency.

 

This test is the method of choice for detecting TALDO, transketolase, and RPI deficiency.

Method Name
A short description of the method used to perform the test

Gas Chromatography Mass Spectrometry (GC-MS)

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Polyols, QN, U

Aliases
Lists additional common names for a test, as an aid in searching

Taldo

Transaldolase deficiency

PPP deficiency

Pentose phosphate pathway

RPI deficiency

Ribose-5-phosphate deficiency

Polyols

Transketolase deficiency

TKT

Sedoheptulokinase deficiency

Specimen Type
Describes the specimen type validated for testing

Urine

Necessary Information

1. Patient's age is required.

2. Biochemical Genetics Patient Information (T602) is recommended, but not required, to be filled out and sent with the specimen to aid in the interpretation of test results.

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Supplies: Urine Tubes, 10 mL (T068)

Specimen Volume: 2 mL

Collection Instructions:

1. Collect a random urine specimen.

2. No preservative.

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

1. Biochemical Genetics Patient Information (T602)

2. If not ordering electronically, complete, print, and send a Biochemical Genetics Test Request (T798) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

1 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

  All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Urine Refrigerated (preferred) 28 days
Frozen 28 days

Useful For
Suggests clinical disorders or settings where the test may be helpful

Diagnosing deficiencies of transaldolase, transketolase, sedoheptulose, or ribose-5-phosphate isomerase

Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request

This is a screening test for disorders of the pentose phosphate pathway such as transaldolase deficiency, transketolase deficiency, sedoheptulokinase deficiency, or ribose-5-phosphate isomerase deficiency.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Polyols are sugar alcohols that have been identified in blood, urine, and cerebrospinal fluid. Characteristic patterns of abnormal polyols may suggest a disorder of the pentose phosphate pathway (PPP), including transaldolase (TALDO) deficiency, transketolase, and ribose-5-phosphate isomerase (RPI) deficiency. The PPP is involved in carbohydrate metabolism and is present in the cytosol of all cells. Two specific functions of the PPP are the production of nicotinamide adenine dinucleotide phosphate (NADPH[+]) and the synthesis of ribose-5-phosphate, a molecule necessary for nucleotide and nucleic acid synthesis. TALDO, transketolase, and RPI deficiency, which have multisystem involvement are recently described disorders of this pathway. Sedoheptulokinase deficiency is also recently described but it’s correlation to disease is unclear as only two unrelated patients from consanguineous families been reported to date. These 2 patients had different multisystem involvement.(1)

 

Transaldolase deficiency is an autosomal recessive disorder caused by a reduction of the enzyme transaldolase. Clinical manifestations are characterized by severe neonatal liver failure, coagulopathy, low serum protein, hypoglycemia, high ammonia, progressive myocardial hypertrophy, and abnormal lactate dehydrogenase with remarkably normal or low transaminases.

 

Patients may present in the antenatal period with maternal HELLP syndrome (hemolysis, elevated liver enzymes, low platelets), hydrops fetalis and oligohydramnios, dysmorphic features, cutis laxa, and hypertrichosis. The clinical course is variable, but acute liver failure with normal transaminases is a common finding. Initially, hepatomegaly is absent, but the spleen may be enlarged. Later, hepatomegaly with liver cirrhosis and mild kidney failure occurs.

 

Ribose-5-phosphate isomerase deficiency is an autosomal recessive disorder caused by a deficiency of the enzyme ribose-5-phosphate isomerase. Clinical manifestations include neurological deficits such as slow progressing leukoencephalopathy and neuropathy. Additionally, spasticity, ataxia, epilepsy, regression, and delayed psychomotor development have been described.

 

Transketolase deficiency is an autosomal recessive disorder characterized by short stature, developmental delay, and congenital heart defects. Dependent on thiamine, transketolase is directly involved in the branch of the pathway that channels excess sugar phosphates to glycolysis.(2) Characteristic polyol patterns in both urine and plasma include elevations of arabitol/xylitol, ribitol, and erythritol. Transketolase deficiency is caused by deleterious biallelic variants in TKT.

 

Sedoheptulokinase deficiency is an autosomal recessive condition characterized by increased excretion of erythritol and sedoheptulose.(3) Relationship to disease is yet unclear as only 2 patients have been described in the literature.

 

Polyols analysis in urine is the method of choice for the biochemical diagnosis of TALDO, transketolase, and RPI deficiency. Abnormal results should be followed with either enzymatic or molecular genetic analysis.

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.

ERYTHRITOL

< or =11 months: <220 mmol/mol creatinine

1-3 years: <267 mmol/mol creatinine

4-17 years: <171 mmol/mol creatinine

>or =18 years: <99 mmol/mol creatinine

 

ARABINITOL

< or =11 months: <140 mmol/mol creatinine

1-3 years: <149 mmol/mol creatinine

4-17 years: <97 mmol/mol creatinine

>or =18 years: <51 mmol/mol creatinine

 

RIBITOL

< or =11 months: <31 mmol/mol creatinine

1-3 years: <31 mmol/mol creatinine

4-17 years: <17 mmol/mol creatinine

>or =18 years: <11 mmol/mol creatinine

 

SEDOHEPTULOSE

< or =11 months: <76 mmol/mol creatinine

1-3 years: <27 mmol/mol creatinine

4-17 years: <28 mmol/mol creatinine

>or =18 years: <22 mmol/mol creatinine

Interpretation
Provides information to assist in interpretation of the test results

An interpretive report will be provided.

 

All profiles are reviewed by the laboratory director and interpretation is based on pattern recognition. A detailed interpretation is given, including an overview of the results and of their significance, a correlation to available clinical information, elements of differential diagnosis, recommendations for additional biochemical testing and in vitro confirmatory studies (enzyme assay, molecular analysis), name and phone number of key contacts who may provide these studies at Mayo Clinic or elsewhere, and a phone number to reach one of the laboratory directors in case the referring physician has additional questions.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

A positive test result is diagnostic of transaldolase deficiency or ribose-5-phosphate isomerase deficiency; however, it is strongly recommended to follow-up with molecular analysis.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Wamelink MM, Ramos RJ, van den Elzen AP, et al. First two unrelated cases of isolated sedoheptulokinase deficiency: A benign disorder?. J Inherit Metab Dis. 2015;38(5):889-894. doi:10.1007/s10545-014-9809-

2. OMIM: 617044. Short Stature, Developmental Delay, and Congenital Heart Defects; SDDHD. Johns Hopkins University; 2016. Last updated April 07, 2021, Accessed September 27, 2024. Available at www.omim.org/entry/617044

3. OMIM: 617213. Sedoheptulokinase Deficiency; SHPKD. Johns Hopkins University; 2016. Accessed September 27, 2024. Available at www.omim.org/entry/617213

4. Eyaid W, Al Harbi T, Anazi S, et al. Transaldolase deficiency: report of 12 new cases and further delineation of the phenotype. J Inherit Metab Dis. 2013;36(6):997-1004

5. Huck JH, Verhoeven NM, Struys EA, et al. Ribose-5-phosphate isomerase deficiency: new inborn error in the pentose phosphate pathway associated with a slowly progressive leukoencephalopathy. Am J Hum Genet. 2004;74(4):745-751

6. Stincone A, Prigione A, Cramer T, et al. The return of metabolism: biochemistry and physiology of the pentose phosphate pathway. Biol Rev Camb Philos Soc. 2015;90(3):927-963. doi:10.1111/brv.12140

7. Wamelink MC, Valayannopoulos V, Jakobs C. Ribose-5-phosphate isomerase deficiency and transaldolase deficiency. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA. eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw Hill; 2019. Accessed September 27, 2024. Available at https://ommbid.mhmedical.com/content.aspx?sectionid=225081431&bookid=2709

Method Description
Describes how the test is performed and provides a method-specific reference

Urine specimens are spiked with a mixture of labeled internal standards, allowed to equilibrate, and evaporated. The dry residue is derivatized to form trimethylsilyl esters then extracted with hexane. Specimens are analyzed by gas chromatography mass spectrometry, selected ion monitoring using ammonia chemical ionization and a stable isotope dilution method.(Jansen G, Muskiet F, Schierbeek H, et al. Capillary gas chromatography profiling of urinary, plasma, and erythrocyte sugars and polyols as their trimethylsilyl derivatives, preceded by a simple and rapid prepurification method. Clin Chim Acta 1986;157(3):277-294, Kaur P, Wamelink MMC, van der Knaap MS, et al. Confirmation of a rare genetic leukoencephalopathy due to a novel bi-allelic variant in RPIA. Eur J Med Genet. 2019;62(8):103708. doi:10.1016/j.ejmg.2019.103708)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Tuesday; Friday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

3 to 7 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

3 months

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their account representative. For assistance, contact Customer Service.

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 instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US 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 Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

82542

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
TALDO Polyols, QN, U 74447-4
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
35824 Erythritol 48107-7
35825 Arabinitol 47829-7
35826 Ribitol 47884-2
35827 Sedoheptulose 78967-7
35829 Interpretation (TALDO) 74448-2
35830 Reviewed By 18771-6

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports