Test Id : PGRBC
Plasmalogens, Blood
Useful For
Suggests clinical disorders or settings where the test may be helpful
Diagnosing patients with possible peroxisomal disorders, such as peroxisomal biogenesis disorders (Zellweger syndrome spectrum) and rhizomelic chondrodysplasia punctata (RCDP), including fatty acyl-CoA reductase 1 (FAR1) deficiency
Evaluating patients with abnormal newborn screen results for X-linked adrenoleukodystrophy who appear to have a different type of peroxisomal disorder, such as a Zellweger syndrome spectrum disorder.
Aiding in the assessment of peroxisomal function
Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request
This test measures plasmalogens and plasmalogen to fatty acid ratios for the purpose of diagnosis of peroxisomal biogenesis disorders (Zellweger syndrome spectrum) and rhizomelic chondrodysplasia punctata (RCDP), including fatty acyl-CoA reductase 1 (FAR1) deficiency.
Highlights
This test analyzes plasmalogens and plasmalogen to fatty acid ratios. Reports include concentrations of C16:0, C18:0 and C18:1 plasmalogens and the ratio of the C16:0 and C18:0 plasmalogens to the respective fatty acid.
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.
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
Rhizomelic Chondrodysplasia Punctata
Fatty Acyl-CoA Reductase 1 Deficiency
Peroxisomal Biogenesis Disorder
Zellweger syndrome
RCDP
RCP
FAR1 Deficiency
PEX disorder
Neonatal ALD
Infantile Refsum
Refsum disease
Specimen Type
Describes the specimen type validated for testing
Whole blood
Additional Testing Requirements
If peroxisomal biogenesis disorders (Zellweger syndrome spectrum) are suspected, also order very long chain fatty acids (POX / Fatty Acid Profile, Peroxisomal [C22-C26], Serum; or POXP / Fatty Acid Profile, Peroxisomal [C22-C26], Plasma), bile acids (BAIPD / Bile Acids for Peroxisomal Disorders, Serum), and pipecolic acid (PIPU / Pipecolic Acid, Random, Urine).
If rhizomelic chondrodysplasia punctata (RCDP) is suspected, also order very long chain fatty acids (POX / Fatty Acid Profile, Peroxisomal [C22-C26], Serum), which includes phytanic and pristanic acid analysis.
Shipping Instructions
Whole blood should be sent refrigerated.
Necessary Information
1. Reason for testing is required
2. Date of blood transfusion, if performed.
3. 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.
ORDER QUESTIONS AND ANSWERS
| Question ID | Description | Answers |
|---|---|---|
| BG726 | Reason for Referral |
Follow up abnormal NBS for C26 LPC MRI findings Molecular findings Skeletal abnormalities Treatment monitoring Not provided |
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Patient Preparation: Specimen must be collected either prior to or 6 weeks after a blood transfusion.
Specimen Type: Whole Blood
Container/Tube:
Preferred: Lavender top (EDTA)
Acceptable: Green top (sodium or lithium heparin), yellow top (ACD solution A or B)
Specimen Volume: 5 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. Biochemical Genetics Patient Information (T602) (recommended, but not required)
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.
3 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 | Refrigerated (preferred) | 14 days | |
| Ambient | 14 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Diagnosing patients with possible peroxisomal disorders, such as peroxisomal biogenesis disorders (Zellweger syndrome spectrum) and rhizomelic chondrodysplasia punctata (RCDP), including fatty acyl-CoA reductase 1 (FAR1) deficiency
Evaluating patients with abnormal newborn screen results for X-linked adrenoleukodystrophy who appear to have a different type of peroxisomal disorder, such as a Zellweger syndrome spectrum disorder.
Aiding in the assessment of peroxisomal function
Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request
This test measures plasmalogens and plasmalogen to fatty acid ratios for the purpose of diagnosis of peroxisomal biogenesis disorders (Zellweger syndrome spectrum) and rhizomelic chondrodysplasia punctata (RCDP), including fatty acyl-CoA reductase 1 (FAR1) deficiency.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Peroxisomes are organelles that carry out essential metabolic functions, including beta-oxidation of very long-chain fatty acids (VLCFA), alpha-oxidation of phytanic acid, and biosynthesis of plasmalogen and bile acids. Peroxisomal disorders include disorders of peroxisomal biogenesis with defective assembly of the entire organelle, and disorders of peroxisome function with single peroxisomal enzyme/transporter defects where the organelle is intact but a specific function is disrupted.
Biochemical abnormalities in peroxisomal biogenesis disorders can include accumulations of VLCFA, phytanic acid, pristanic acid, pipecolic acid, bile acids, and reduced plasmalogens. The differential diagnosis of these disorders is based on recognition of clinical phenotypes combined with a series of biochemical tests to assess peroxisomal function and structure. These include measurements and ratios of VLCFA, phytanic acid, and its metabolite pristanic acid (POX / Fatty Acid Profile, Peroxisomal [C22-C26], Serum; or POXP / Fatty Acid Profile, Peroxisomal [C22-C26], Plasma), pipecolic acid (PIPA / Pipecolic Acid, Serum; or PIPU / Pipecolic Acid, Random, Urine), bile acids (BAIPD / Bile Acids for Peroxisomal Disorders, Serum), and plasmalogens.
Peroxisomal biogenesis disorders (PBD) include Zellweger syndrome spectrum disorders, which are clinically diverse and range in severity from neonatal lethal (Zellweger syndrome) to more variable clinical courses in neonatal adrenoleukodystrophy and infantile Refsum disease. Affected children typically have hypotonia, poor feeding, distinctive facial features, seizures, and liver dysfunction. Other features can include retinal dystrophy, hearing loss, developmental delays, and bleeding episodes.
Rhizomelic chondrodysplasia punctata (RCDP) is a malformation disorder characterized by rhizomelic shortening, chondrodysplasia punctata, cataracts, intellectual disability, and seizures; however, it can have a milder phenotype with only cataracts and chondrodysplasia punctata. Currently, there are 5 clinical types of rhizomelic chondrodysplasia punctata: RCDP 1, 2, 3, 4 (also known as FAR1 deficiency) and 5. RCDP 1 is the classical form that presents in infancy with skeletal manifestations, including rhizomelic shortening, cataracts, and severe to profound postnatal growth deficiency. Infants with RCDP 1 have developmental delay, and later, intellectually disability. The majority of children with RCDP 1 do not survive beyond the first decade of life. RCDP 1 is an autosomal recessive disorder caused by disease-causing variants in the PEX7 gene. RCDP 2 and 3 have clinical phenotypes similar to RCDP 1 and may be distinguished by plasmalogen deficiency. RCDP 2 and 3 are autosomal recessive conditions caused by disease-causing variants in GNPAT and AGPS genes, respectively. Individuals with RCDP 5 have a milder phenotype when compared to classic RCDP 1, with most individuals able to achieve self-feeding, independent ambulation, and development of limited language skills. RCDP5 results in less pronounced reduction in plasmalogens compared to RCDP 1. This newly recognized subtype of RCDP is an autosomal recessive disorder caused by disease-causing variants in the PEX5 gene.
The typical biochemical profile for RCDP shows reduced plasmalogens, elevated phytanic acid, and normal VLCFA. Confirmatory testing via molecular analysis for all types of RCDP is available (PDGP / Peroxisomal Disorder Gene Panel, Varies).
Fatty acyl-CoA reductase 1 (FAR1) deficiency, also known as RCDP type 4, is an autosomal recessive peroxisomal disorder caused by disease-causing variants in the FAR1 gene that result in early-onset epilepsy, microcephaly, cataracts, postnatal growth deficiency, and intellectual disability. Unlike RCDP, however, infants with FAR1 deficiency have no skeletal abnormalities. The biochemical profile for FAR1 deficiency includes reduced plasmalogens, normal to elevated phytanic acid, and normal VLCFA.
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.
Hexadecanal-Dimethylacetal, C16:0 DMA:
> or =6.00 mcg/mL
Octadecanal-Dimethylacetal, C18:0 DMA:
> or =9.00 mcg/mL
9Z-Octadecenal-DiMethylacetal C18:1 DMA:
> or =2.00 mcg/mL
C16:0 DMA/C16:0:
> or =0.018
C18:0 DMA/C18:0:
> or =0.040
Interpretation
Provides information to assist in interpretation of the test results
Reports include concentrations of C16:0, C18:0 and C18:1 plasmalogens and the ratio of the C16:0 and C18:0 plasmalogens to the respective fatty acid. When no significant abnormalities are detected, a simple descriptive interpretation is provided.
A profile of reduced plasmalogens and abnormal very long-chain fatty acids (VLCFA), as well as possible abnormalities in pipecolic acid and bile acids, can be consistent with a diagnosis of a peroxisomal biogenesis disorder (Zellweger syndrome spectrum).
A profile of reduced plasmalogens, elevated phytanic acid, and normal VLCFA is consistent with a diagnosis of rhizomelic chondrodysplasia punctata, such as RCDP type 1 or 2, FAR1 deficiency (RCDP type 4), or other types of RCDP.
Positive test results could be due to a genetic or nongenetic condition. Additional confirmatory testing would be required to differentiate between these causes.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
The results of testing performed in erythrocytes are invalid following a transfusion; therefore, collect specimen either prior to or 6 weeks after a blood transfusion.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Braverman NE, Moser AB, Steinberg SJ, Fallatah WF, Duker A, Bober M. Rhizomelic chondrodysplasia punctata type 1. In: Adam MP, Ardinger HH, Pagon RA, et al, eds. GeneReviews [Internet]. University of Washington, Seattle; 2001. Updated January 30, 2020. Accessed May 25, 2023. Available at: www.ncbi.nlm.nih.gov/books/NBK1270/
2. Buchert R, Tawamie H, Smith C, et al. A peroxisomal disorder of severe intellectual disability, epilepsy, and cataracts due to fatty acyl-CoA reductase 1 deficiency. Am J Hum Genet. 2014;95(5):602-610
3. Baroy T, Koster J, Stromme P, et al: A novel type of rhizomelic chondrodysplasia punctata, RCDP5, is caused by a loss of the PEX5 long isoform. Hum Mol Genet. 2015;24(20):5845-5854
4. Braverman NE, Moser AB. Functions of plasmalogen lipids in health and disease. Biochim Biophys Acta. 2012;1822(9):1442-1452
Method Description
Describes how the test is performed and provides a method-specific reference
This test measures C16:0, C18:1 and C18:0 plasmalogens in red blood cells as a diagnostic marker for peroxisomal disorders as well as C16:0 and C18:0 fatty acids for normalization. Briefly, samples, standards and quality control are mixed with internal standards and derivatization and extraction is performed. Plasmalogens and fatty acids are then extracted from solution, transferred to a new tube, dried down under nitrogen, reconstituted, and analyzed by gas chromatography 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.
Tuesday
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 :
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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.
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 |
|---|---|---|
| PGRBC | Plasmalogens, RBC | 74634-7 |
| 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.
|
|---|---|---|
| 609676 | Hexadecanal-Dimethylacetal, C16 DMA | 104681-2 |
| 609677 | Octadecanal-Dimethylacetal, C18 DMA | 104680-4 |
| 609678 | 9Z-Octadecenal-DiMe acetal C18:1DMA | 104679-6 |
| 609681 | C16 DMA/C16:0 | 104677-0 |
| 609682 | C18 DMA/C18:0 | 104678-8 |
| BG726 | Reason for Referral | 42349-1 |
| 609684 | Reviewed By | 18771-6 |
| 609685 | Interpretation | 59462-2 |