Supporting the biochemical diagnosis of multiple sulfatase deficiency
This test is not useful for carrier detection.
Test Id | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
MPSBS | Mucopolysaccharidosis, BS | Yes | No |
If results are normal, testing is complete.
If results indicate multiple sulfatase deficiency, quantitation of heparan sulfate, dermatan sulfate and keratan sulfate may be performed at an additional charge.
Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)
GALNS
Galactosamine-6-sulfate sulfatase
Heparan-N-sulfatase
Heparan sulfate sulfatase
I2S
Multiple Sulfatase deficiency
MSD
Iduronate-2-sulfatase
N-acetylgalactosamine-6-sulfatase
SGSH
SUMF1
If results are normal, testing is complete.
If results indicate multiple sulfatase deficiency, quantitation of heparan sulfate, dermatan sulfate and keratan sulfate may be performed at an additional charge.
Whole blood
1. Patient's age is required.
2. Reason for testing is required.
Question ID | Description | Answers |
---|---|---|
BG755 | Reason for Referral |
Rule out MSD Follow up of known MSD Multiple Sulfatase deficiency Not Provided |
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, PerkinElmer 226 filter paper, Munktell filter paper, or blood collected in tubes containing ACD or EDTA and dried on filter paper.
Specimen Volume: 2 Blood spots
Collection Instructions:
1. An alternative blood collection option for a patient 1 year of age or older is a fingerstick. For detailed instructions, see How to Collect Dried Blood Spot Samples.
2. At least 2 spots should be complete (ie, unpunched).
3. Let blood dry on filter paper at room temperature in a horizontal position for a minimum of 3 hours.
4. Do not expose specimen to heat or direct sunlight.
5. Do not stack wet specimens.
6. Keep specimen dry.
Specimen Stability Information: Refrigerated (preferred) 60 days/Ambient 7 days/Frozen 60 days
Additional Information:
1. For collection instructions, see Blood Spot Collection Instructions
2. For collection instructions in Spanish, see Blood Spot Collection Card-Spanish Instructions (T777)
3. For collection instructions in Chinese, see Blood Spot Collection Card-Chinese Instructions (T800)
Acceptable:
Specimen Type: Whole Blood
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Yellow top (ACD)
Specimen Volume: 2 mL
Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.
Specimen Stability Information: Refrigerate (preferred) 7 days/Ambient 48 hours
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.
Blood Spots: 1
Whole Blood: 0.5 mL
Blood spot specimen that shows serum rings or has multiple layers | Reject |
Insufficient specimen | Reject |
Unapproved filter papers | Reject |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole blood | Varies |
Supporting the biochemical diagnosis of multiple sulfatase deficiency
This test is not useful for carrier detection.
If results are normal, testing is complete.
If results indicate multiple sulfatase deficiency, quantitation of heparan sulfate, dermatan sulfate and keratan sulfate may be performed at an additional charge.
Multiple sulfatase deficiency (MSD) is a rare autosomal recessive lysosomal disorder caused by mutations in the sulfatase-modifying factor 1 (SUMF1) gene. SUMF1 encodes for a formylglycine-generating enzyme that performs a critical posttranslational modification necessary for activation of all human sulfatases, including arylsulfatase A and B. The clinical features of MSD encompass symptoms of every single sulfatase deficiency, including metachromatic leukodystrophy (MLD), the mucopolysaccharidoses, X-linked ichthyosis, and chondrodysplasia punctata type I. Age of onset and clinical severity are variable and correspond with the level of residual enzyme activity. A severe neonatal form of MSD closely overlaps the clinical presentation of the mucopolysaccharidoses, but it is often fatal within 1 year. Late-infantile MSD (onset 0-2 years) accounts for most cases and is characterized by a clinical presentation similar to MLD.
A diagnostic workup for MSD demonstrates reduced enzyme activity of several sulfatase enzymes including those on this panel (iduronate-2-sulfatase, heparan sulfate sulfatase, galactosamine-6-sulfate sulfatase, and arylsulfatase B). Individuals with MSD typically have an increased urinary excretion of sulfatides as well as increased urinary glycosaminoglycans, therefore a combined analysis of urine ceramide trihexoside, mucopolysaccharides, oligosaccharides, and sulfatides (LSDS/ Lysosomal Storage Disorders Screen, Random, Urine) may support a diagnosis. Molecular genetic analysis of the SUMF1 gene (CGPH / Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies; specify Gene List ID: IEMCP-PCUBX1) allows for detection of disease-causing variants in affected patients and subsequent carrier detection in relatives.
Iduronate-2-sulfatase: >4.30 nmol/mL/hour
Heparan-N-sulfatase: >0.06 nmol/mL/hour
N-acetylgalactosamine-6-sulfatase: >0.70 nmol/mL/hour
An interpretive report will be provided.
Abnormal results are not sufficient to establish a diagnosis of a particular disease. To verify a preliminary diagnosis based on this assay, additional biochemical or molecular genetic analyses are required.
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 genetic analysis), and a phone number to reach one of the laboratory directors in case the referring physician has additional questions.
Individuals with pseudodeficiency alleles can show reduced enzyme activity.
Carrier status (heterozygosity) for these conditions cannot be reliably detected.
1. Neufeld EF, Muenzer J. The mucopolysaccharidoses. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA. eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; Accessed July 14, 2023. https://ommbid.mhmedical.com/content.aspx?bookid=2709§ionid=225544161
2. Hopwood JJ, Ballabio A. Multiple sulfatase deficiency and the nature of the sulfatase family. In: Valle DL, Antonarakis S, Ballabio A, Beaudet AL, Mitchell GA. eds. The Online Metabolic and Molecular Bases of Inherited Disease. McGraw-Hill; Accessed July 14, 2023. https://ommbid.mhmedical.com/content.aspx?bookid=2709§ionid=225546905
One dried blood spot sample (DBS) is incubated with a mix of substrate and internal standard (IS) for iduronate 2-sulfatase, heparan N-sulfatase, alpha-N-acetylglucosaminidase, N-acetylgalactosamine-sulfate, beta-galactosidase, arylsulfatase B, beta-glucuronidase, and tripeptidyl peptidase 1. A second DBS sample is incubated with a mix of substrate and IS for acetyl-CoA:alpha-glucosaminide N-acetyltransferase; and a third DBS sample with a mix of substrate and IS for palmitoyl-protein thioesterase 1. Following overnight incubation, the samples are combined, extracted by liquid-liquid extraction, and analyzed by tandem mass spectrometry.(Unpublished Mayo method)
Thursday
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.
82657
83864 (if appropriate)
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
MSDBS | Multiple sulfatase deficiency, BS | 104116-9 |
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.
|
---|---|---|
BG755 | Reason for Referral | 42349-1 |
618430 | Iduronate-2-sulfatase | 79462-8 |
618431 | Heparan-N-sulfatase | 104113-6 |
618432 | N-acetylgalactosamine-6-sulfatase | 88019-5 |
618433 | Interpretation | 59462-2 |
618429 | Reviewed By | 18771-6 |
Change Type | Effective Date |
---|---|
New Test | 2023-10-17 |