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Test Code CHRCBM Chromosome Analysis, Congenital Disorders, Blood

Additional Codes







Useful For

Diagnosis of congenital chromosome abnormalities, including aneuploidy, structural abnormalities, and balanced rearrangements

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
_M15A Metaphases, 1-14 No, (Bill Only) No
_M19 Metaphases, 15-20 No, (Bill Only) No
_MG19 Metaphases, >20 No, (Bill Only) No
_KTG2 Karyotypes, >2 No, (Bill Only) No
_STAC Ag-Nor/CBL Stain No, (Bill Only) No

Testing Algorithm

This test includes a charge for cell culture of fresh specimens and professional interpretation of results. Analysis charges will be incurred for total work performed, and generally include 2 banded karyograms and the analysis of 20 metaphase cells. If no metaphase cells are available for analysis, no analysis charges will be incurred. If additional analysis work is required, additional charges may be incurred.


This test is not appropriate for detecting acquired chromosome abnormalities. If this test is ordered with a reason for referral indicating a hematologic disorder, the test will be cancelled and CHRHB / Chromosome Analysis, Hematologic Disorders, Blood will be performed as the appropriate test.


A chromosomal microarray study (CMACB / Chromosomal Microarray, Congenital, Blood) is recommended as the first-tier test (rather than a congenital chromosome study) to detect clinically relevant gains or losses of chromosomal material for individuals with multiple anomalies not specific to well-delineated genetic syndromes, individuals with apparently nonsyndromic developmental delay or intellectual disability, and individuals with autism spectrum disorders.

Method Name

Cell Culture with Mitogens followed by Chromosome Analysis

Reporting Name

Chromosomes, Congenital, Blood

Specimen Type

Whole blood

Specimen Required

Provide a reason for referral with each specimen. The laboratory will not reject testing if this information is not provided, but appropriate testing and interpretation may be compromised or delayed.


Submit only 1 of the following specimens:


Specimen Type: Whole blood

Container/Tube: Green top (sodium heparin)

Specimen Volume: 5 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Other anticoagulants are not recommended and are harmful to the viability of the cells.

3. Label specimen as whole blood.


Specimen Type: Cord whole blood

Container/Tube: Green top (sodium heparin)

Specimen Volume: As much as possible

Collection Instructions:

1. Invert several times to mix blood.

2. Other anticoagulants are not recommended and are harmful to the viability of the cells.

3. Label specimen as cord blood.

Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time
Whole blood Ambient (preferred)

Reject Due To

Note: No specimen should be rejected. If specimen not received at appropriate temperature or in wrong anticoagulant, include note to laboratory. Contact the laboratory with questions.

Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Samples processed Monday through Sunday. Results reported Monday through Friday, 8 a.m. to 5 p.m.

Analytic Time

10 days

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

88230, 88291- Tissue culture for Lymphocytes, Interpretation and report

88262 w/modifier 52-Chromosome analysis less than15 cells (if appropriate)

88262-Chromosome analysis with 15 to 20 cells (if appropriate)

88262, 88285-Chromosome analysis with greater than 20 cells (if appropriate)

88280-Chromosome analysis, greater than 2 karyotypes (if appropriate)

88283-Additional specialized banding technique (if appropriate) 


LOINC Code Information

Test ID Test Order Name Order LOINC Value
CHRCB Chromosomes, Congenital, Blood In Process


Result ID Test Result Name Result LOINC Value
52366 Result Summary 50397-9
52368 Interpretation 69965-2
52367 Result 82939-0
CG775 Reason for Referral 42349-1
52369 Specimen 31208-2
52370 Source 31208-2
52372 Method 49549-9
52371 Banding Method 62359-5
54630 Additional Information 48767-8
52373 Released By 18771-6


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 (T576) is available in Special Instructions.