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HelpOrder Code LABBCMAC Chromosomal Microarray, Congenital, Blood
Useful For
First-tier, postnatal testing for individuals with multiple anomalies that are not specific to well-delineated genetic syndromes, apparently nonsyndromic developmental delay or intellectual disability, or autism spectrum disorders as recommended by the American College of Medical Genetics and Genomics
Follow-up testing for individuals with unexplained developmental delay or intellectual disability, autism spectrum disorders, or congenital anomalies with a previously normal conventional chromosome study
Determining the size, precise breakpoints, gene content, and any unappreciated complexity of abnormalities detected by other methods such as conventional chromosome and fluorescence in situ hybridization studies
Determining if apparently balanced abnormalities identified by previous conventional chromosome studies have cryptic imbalances, since a proportion of such rearrangements that appear balanced at the resolution of a chromosome study are actually unbalanced when analyzed by higher-resolution chromosomal microarray
Assessing regions of homozygosity related to uniparental disomy or identity by descent
Special Instructions
- Informed Consent for Genetic Testing
- Prader-Willi and Angelman Syndromes: Laboratory Approach to Diagnosis
- Chromosomal Microarray Patient Information
- GenomeConnect Patient Portal
- Family Member Phenotype Information for Genomic Testing
- Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm
- Informed Consent for Genetic Testing (Spanish)
Method Name
Chromosomal Microarray (CMA)
Reporting Name
Chromosomal Microarray, BloodSpecimen Type
Whole bloodOrdering Guidance
This test is not appropriate for detecting acquired copy number changes and excessive homozygosity. If this test is ordered with a reason for testing indicating a hematological disorder, the test will be canceled and CMAH / Chromosomal Microarray, Hematologic Disorders, Varies will be added and performed as the appropriate test.
Shipping Instructions
Advise Express Mail or equivalent if not on courier service.
Necessary Information
The reason for testing is required.
Specimen Required
This test requires 2 blood specimens: 1 sodium heparin and 1 EDTA.
Submit only 1 of the following specimen types:
Specimen Type: Whole blood
Container/Tube: Green top (sodium heparin) and lavender top (EDTA)
Specimen Volume: 3-mL EDTA tube and 4-mL sodium heparin tube
Collection Instructions:
1. Invert several times to mix blood.
2. Send whole blood specimens in original tubes. Do not aliquot.
Specimen Type: Cord blood
Container/Tube: Green top (sodium heparin) and lavender top (EDTA)
Specimen Volume: 3-mL EDTA tube and 4-mL sodium heparin tube
Note: The lab will attempt testing on a minimum of 1-mL whole blood, EDTA preferred.
Collection Instructions:
1. Invert several times to mix blood.
2. Send cord blood specimens in original tubes. Do not aliquot.
3. Label specimen as cord blood.
Specimen Minimum Volume
2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole blood | Ambient (preferred) | ||
| Refrigerated | |||
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Reference Values
An interpretive report will be provided.
Method Description
DNA extracted from the patient's peripheral blood is labeled and hybridized to the microarray. Following hybridization, the microarray is scanned, and the intensity of signals is measured and compared to a reference data set. These data are used to determine copy number changes and regions of excess homozygosity. Chromosomal microarray data alone does not provide information about the structural nature of an imbalance and some abnormal results may be characterized by fluorescence in situ hybridization, limited chromosome analysis, or additional techniques.(Unpublished Mayo method)
Day(s) Performed
Monday through Sunday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
81229
Testing Algorithm
The following algorithms are available:
-Epilepsy: Unexplained Refractory and/or Familial Testing Algorithm
-Prader-Willi and Angelman Syndromes: Laboratory Approach to Diagnosis
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. Chromosomal Microarray Patient Information (T665)
3. Family Member Phenotype Information for Genomic Testing
4. If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.