Test ID: SPHT
Sphingomyelinase, Fibroblasts
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Diagnosis of Niemann-Pick disease types A and B
Genetics Test Information Provides information that may help with selection of the correct test or proper submission of the test request
Diagnostic test for Niemann-Pick types A and B. Not recommended for carrier detection.
Additional Tests Lists test(s) that are always performed, at an additional charge, with the initial test(s)
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| FIBR | Fibroblast Culture | Yes | Yes |
| CRYOB | Cryopreserve for Biochem Studies | No | Yes |
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
When this test is ordered, a fibroblast culture and cryopreservation for biochemical studies will always be performed at an additional charge. However, for multiple lysosomal enzyme assays on a patient utilizing fibroblast culture, only 1 culture is required regardless of the number of enzyme assays ordered. If viable cells are not obtained within 10 days, client will be notified.
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Method Name A short description of the method used to perform the test
SPHT/8481: Colorimetric Enzyme Assay
CRYOB/88832: Fibroblast Subculture Followed by Cryopreservation and Storage
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Niemann Pick B
Niemann Pick Disease (NPD)
Niemann Pick Disease Type A
Niemann Pick Disease Type B
Niemann Pick IA
Niemann Pick Type IA
Niemann-Pick A
Niemann-Pick B
Niemann-Pick Disease
Niemann-Pick Disease Type A
Niemann-Pick Disease Type B
Niemann-Pick IA
Niemann-Pick Type IA
NP A
NP B
NPD (Niemann-Pick Disease)
Sphingomyelin Lipidosis
Sphingomyelinase Deficiency
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.
This test is not recommended for prenatal testing.
Forms: New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (Supply T576) is available in Special Instructions.
Submit only 1 of the following specimens:
Specimen Type: Cultured fibroblasts
Container/Tube: T-75 or T-25 flask
Specimen Volume: 1 full T-75 flask or 2 full T-25 flasks
Specimen Stability Information: Ambient/Refrigerated <24 hours
Specimen Type: Skin biopsy
Container/Tube: Sterile container with any standard cell culture media (eg, minimal essential media, RPMI 1640). The solution should be supplemented with 1% penicillin and streptomycin. Tubes can be supplied upon request (Eagle's minimum essential medium with 1% penicillin and streptomycin [Supply T115]).
Specimen Volume: 4-mm punch
Specimen Stability Information: Refrigerated/Ambient
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.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | Specimen in formalin or fixative preservative |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Tissue | Varies | |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Niemann-Pick disease (NPD) types A and B result from a deficiency of acid sphingomyelinase, which causes accumulation of sphingomyelin in the organs and tissues of affected individuals. Classification of individuals as having type A or type B is based on age of onset as well as the severity of symptoms. NPD types A and B are inherited in an autosomal recessive manner. Although there is a higher frequency of type A among the Ashkenazi Jewish population, both types are pan-ethnic.
NPD type A is a severe neurodegenerative disorder of infancy characterized by failure to thrive, hepatosplenomegaly, interstitial lung disease, neurologic impairment, and regression of developmental milestones typically leading to death by 2 to 3 years of age. All individuals with NPD type A will eventually develop a cherry-red maculae. Bone marrow biopsy will reveal histochemically characteristic Niemann-Pick foam cells.
NPD type B is characterized by later onset, milder manifestations, and a much more variable clinical presentation. Most patients are diagnosed in childhood when liver or spleen enlargement is detected during a routine physical examination. Common symptoms include hyperlipidemia and pulmonary involvement. In some cases, severe liver disease is present. Generally, nervous system function and intelligence are normal. Most individuals survive into adulthood.
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.
1.53-7.18 U/g of cellular protein
Interpretation Provides information to assist in interpretation of the test results
Deficiency of sphingomyelinase can be demonstrated in cultured skin fibroblasts from patients with the most severe types (types A and B). Values expected in Niemann-Pick disease are <1.0 U/g of cellular protein.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Interfering factors include:
-Lack of viable cells or bacterial contamination
-Failure to transport tissue in an appropriate media
-Excessive transport time
-Exposure of the specimen to temperature extremes (freezing or >30 degrees C)
This test is not useful for Niemann-Pick type C detection (see NIEM/9313 Niemann-Pick Type C Detection, Fibroblasts).
Level of residual enzyme activity is not a reliable indicator or predictor of severity.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Gal AE, Brady RO, Hibbert SR, Pentchev PG: A practical chromogenic procedure for the detection of homozygotes and heterozygous carriers of Niemann-Pick disease. N Engl J Med 1975;293:632-636
2. McGovern MM, Schuchman EH: Acid Sphingomyelinase Deficiency, Available from URL: http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=npab Reviewed June 25, 2009
3. Schuchman EH: The pathogenesis and treatment of acid sphingomyelinase-deficient Niemann-Pick disease. Int J Clin Pharmacol Ther 2009;47 Suppl 1:S48-57
Method Description Describes how the test is performed and provides a method-specific reference
The artificial substrate, 2-N-(hexadecanoyl)amino-4-nitrophenyl-phosphoryl-choline hydroxide, is cleaved by sphingomyelinase at pH 4.5 to yield the yellow sodium phenolate product plus phosphorylcholine. Thus, this analogue is a reliable chromogenic reagent for the diagnosis of patients with Niemann-Pick disease by using cultured skin fibroblasts.(Gal AE, Brady RO, Hibbert SR, Pentchev PG: A practical chromogenic procedure for the detection of homozygotes and heterozygous carriers of Niemann-Pick disease. N Engl J Med 1975;293:632-636)
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.
Varies
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.
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.
82657-Sphingomyelinase
88233-Fibroblast culture
88240-Cryopreservation for biochemical studies
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 |
|---|---|---|
| 30035 | Specimen | 31208-2 |
| 30036 | Specimen ID | N/A |
| 30037 | Source | N/A |
| 30038 | Order Date | N/A |
| 30039 | Reason For Referral | 42349-1 |
| 30043 | Method | In Process |
| 30044 | Sphingomyelinase, Fibroblasts | In Process |
| 30045 | Interpretation | 59462-2 |
| 30046 | Amendment | In Process |
| 30047 | Reviewed By | N/A |
| 30048 | Release Date | N/A |
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