Test Id : ASMW
Acid Sphingomyelinase, Leukocytes
Useful For
Suggests clinical disorders or settings where the test may be helpful
Investigation of possible diagnosis of Niemann-Pick disease types A and B
This test is not recommended for carrier detection because of the wide range of enzymatic activities observed in carriers and noncarriers.
Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request
This test provides diagnostic testing for patients with decreased acid sphingomyelinase activity on newborn screen or with clinical signs and symptoms suspicious for Niemann-Pick type A or B.
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
For more information see Newborn Screen Follow-up for Acid Sphingomyelinase Deficiency
If the patient has abnormal newborn screening results for Niemann- Pick disease, refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)
Method Name
A short description of the method used to perform the test
Flow Injection Analysis-Tandem Mass Spectrometry (FIA-MS/MS)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
Acid Sphingomyelinase Deficiency
ASM Deficiency
Niemann-Pick Disease
Niemann-Pick type A
Niemann-Pick type B
NPD
Sphingomyelinase Deficiency
NPA
NPB
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
For more information see Newborn Screen Follow-up for Acid Sphingomyelinase Deficiency
If the patient has abnormal newborn screening results for Niemann- Pick disease, refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)
Specimen Type
Describes the specimen type validated for testing
Whole Blood ACD
Shipping Instructions
For optimal isolation of leukocytes, it is recommended the specimen arrive refrigerated within 6 days of collection to be stabilized. Collect specimen Monday through Thursday only and not the day before a holiday. Specimen should be collected and packaged as close to shipping time as possible.
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Container/Tube:
Preferred: Yellow top (ACD solution B)
Acceptable: Yellow top (ACD solution A) or lavender top (EDTA)
Specimen Volume: 6 mL
Collection Instructions: Send specimen in original tube. Do not aliquot.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:
-Informed Consent for Genetic Testing (T576)
-Informed Consent for Genetic Testing-Spanish (T826)
2. Biochemical Genetics Patient Information (T602)
3. 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.
2 mL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
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 |
|---|---|---|---|
| Whole Blood ACD | Refrigerated (preferred) | 6 days | |
| Ambient | 6 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Investigation of possible diagnosis of Niemann-Pick disease types A and B
This test is not recommended for carrier detection because of the wide range of enzymatic activities observed in carriers and noncarriers.
Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request
This test provides diagnostic testing for patients with decreased acid sphingomyelinase activity on newborn screen or with clinical signs and symptoms suspicious for Niemann-Pick type A or B.
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
For more information see Newborn Screen Follow-up for Acid Sphingomyelinase Deficiency
If the patient has abnormal newborn screening results for Niemann- Pick disease, refer to the appropriate American College of Medical Genetics and Genomics Newborn Screening ACT Sheet.(1)
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Niemann-Pick disease (NPD) types A (NPA) and B (NPB) are autosomal recessive lysosomal storage disorders affecting metabolism of specific lipids within cells. NPA and NPB are caused by a deficiency of sphingomyelinase, which results in extensive storage of sphingomyelin and cholesterol in the liver, spleen, lungs, and, to a lesser degree, brain. NPA disease is more severe than NPB and is characterized by early onset with feeding problems, dystrophy, persistent jaundice, development of hepatosplenomegaly, neurological deterioration, deafness, and blindness, leading to death by age 3. NPB disease is limited to visceral symptoms with survival into adulthood. Some patients have been described with intermediary phenotypes. Large lipid-laden foam cells are characteristic of the disease. Approximately 50% of cases have cherry-red spots in the macula.
The combined prevalence of NPA and NPB is estimated to be 1 in 250,000. NPA and NPB are inherited in an autosomal recessive manner and are caused by variants in the SMPD1 gene. Although there is a higher frequency of type A among the Ashkenazi Jewish population, both types are panethnic. Individuals with NPD types A and B typically have elevations of lyso-sphingomyelin and lyso-sphingomyelin 509 combined with elevations of the oxysterols cholestane-3 beta, 5 alpha, 6 beta-triol (COT) and 7-ketocholesterol (7-KC). (OXNP / Oxysterols, Plasma; OXYWB / Oxysterols, Blood; OXYBS / Oxysterols, Blood Spot). Molecular genetic testing for NPA and NPB disease is also available (CGPH / Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies; specifcy SMPD1 Gene List ID: IEMCP-W6S9XD).
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.
> or =0.32 nmol/hour/mg protein
An interpretative report will be provided.
Interpretation
Provides information to assist in interpretation of the test results
Values below the reference range are consistent with a diagnosis for Niemann-Pick types A and B.
When abnormal results are detected, 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, 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
This test can give false-positive acid sphingomyelinase results. OXYBS / Oxysterols, Blood Spot may be ordered as a confirmatory test.
Additional biochemical or molecular testing is recommended to confirm a diagnosis if an enzyme deficiency is detected by this screening test.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Newborn Screening ACT Sheet [Decreased acid sphingomyelinase] Acid Sphingomyelinase Deficiency (ASMD). American College of Medical Genetics and Genomics; 2022. Revised May 2022. Accessed June 10, 2024. Available at www.acmg.net/PDFLibrary/Niemann-Pick.pdf
2. Elliott S, Buroker N, Cournoyer JJ, et al: Pilot study of newborn screening for six lysosomal storage diseases using Tandem Mass Spectrometry. Mol Genet Metab. 2016 Aug;118(4):304-309
3. Matern D, Gavrilov D, Oglesbee D, Raymond K, Rinaldo P, Tortorelli S: Newborn screening for lysosomal storage disorders. Semin Perinatol. 2015 Apr;39(3):206-216
4. Schuchman EH, Desnick RJ: Niemann-Pick disease types A and B: acid sphingomyelinase deficiencies. In: Valle D, Antonarakis S, Ballabio A, Beaudet A, Mitchell GA, eds. The Online Metabolic Bases of Inherited Disease. McGraw-Hill; 2019. Accessed May 26, 2021. Available athttps://ommbid.mhmedical.com/content.aspx?sectionid=225545671&bookid=2709
5. Wasserstein MP, Schuchman EH: Acid sphingomyelinase deficiency. In: Adam MP, Ardinger HH, Pagon RA, et al, eds. GeneReviews. [Internet]. University of Washington, Seattle; 2006. Updated February 25, 2021. Accessed May 26, 2021. Available at www.ncbi.nlm.nih.gov/books/NBK1370/
6. Schuchman EH, Desnick RJ: Types A and B Niemann-Pick disease. Mol Genet Metab. 2017 Jan-Feb;120(1-2)27-33
Method Description
Describes how the test is performed and provides a method-specific reference
The specimens are incubated with a mix of substrate and internal standard for acid sphingomyelinase ,beta-glucocerebrosidase , acid alpha-glucosidase , alpha-galactosidase , galactocerebrosidase and alpha-L-iduronidase . The sample is then purified by liquid-liquid extraction. The extract is evaporated and reconstituted before analysis by tandem mass spectrometry.(Unpublished Mayo method)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
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.
Preanalytical processing: Monday through Saturday.
Assay performed: Monday, Wednesday
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.
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
Indicates the location of the laboratory that performs the test
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.
CPT codes are provided by the performing laboratory.
82657
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 |
|---|---|---|
| ASMW | Acid Sphingomyelinase, Leukocytes | 24101-8 |
| 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.
|
|---|---|---|
| 606264 | Acid Sphingomyelinase, Leukocytes | 24101-8 |
| 606265 | Interpretation | 59462-2 |
| 606266 | Reviewed By | 18771-6 |