Sign in →

Test Code LAB1797 Constitutional Karyotype

Additional Codes

CH-KARY

Clinical System Name

Constitutional Karyotype

Synonyms

Chromosome study

Description

This test will detect abnormalities in chromosome number, large chromosomal duplications and deletions and other large structural rearrangements.  G-banded karyotyping will also detected balanced chromosome rearrangements.  This test is appropriate for an individual with any of the following findings:

  • chromosomal aneuoploidy syndromes, such as Down syndrome
  • a family history of chromosomal rearrangement
  • a personal history of multiple miscarriages
  • sex determination

Note: In most cases, blood samples from newborns (less than 2 weeks old) will have a preliminary karyotype result issued in 24-72 hours (depending on specimen yield) after the specimen is processed in the cytogenetics lab.  Note that samples received after 3pm may not get processed the same day.  Call the laboratory with questions.

  

Sample Requirements

Note: Extracted DNA is not an acceptable specimen type for karyotype

 

Specimen: Whole Blood

Container(s): Dark Green/Sodium Heparin (no serum separator)

Preferred Vol:  5.0 mL (2.0 mL for infants <24 months)

Minimum Vol:  3.0 mL (1.0 mL for infants <24 months); do not use micro tubes for collection

 

Note:  Keep sample at room temperature; deliver to the lab promptly.  Samples received after 3 pm will be set up the following day. 

 

Note:  For patients who have had a whole blood transfusion, wait 10 days post transfusion to draw for Cytogenetics.  No wait time is necessary if the patient received red cells or plasma.   

 

Specimen: Cord Blood

Container(s): Dark Green/Sodium Heparin (no serum separator)

Preferred Vol:  5.0 mL

Minimum Vol:  1.0 mL

 

For specimen requirements for skin, tissue or fibroblasts see Chromosomes - Fibroblasts.

Processing Instructions

Reject due to: Collected in microtainer.  Extracted DNA

Spin: N

Aliquot: N

Temp: RT

Storage location:  

  • Days: Monday-Friday, 07:00-17:00, transport specimen, a copy of the requistion (if the order was transcribed from a paper req), and labels to 4th floor Cytogenetics (station #181). 
  • Days: Saturday-Sunday, 09:00-15:00, transport specimen, a copy of the requistion (if the order was transcribed from a paper req), and labels to 4th floor Cytogenetics (station #181).
  • Eves/Nights: Store specimen, a copy of the requistion (if the order was transcribed from a paper req), and labels in the Cytogenetics room temp box in CPA.

 

Off-site collection:  Keep sample at room temperature.  Transport specimen to Seattle Children's Laboratory by overnight shipping.  Samples received after 3 pm will be set up the following day.

Stability

Temperature Time
Room temp 3 d
Refrigerated No
Frozen No

 

Note: For optimal results, it is best to submit sample as soon as possible.

Availability

STAT Performed TAT
N Daily 1-3 w

 

Performing Laboratory

Seattle Children's Hospital

Department

Department: Cytogenetics Laboratory 

Phone number: 206-987-3961

 

Lab Client Services: 206-987-2617, labclientservices@seattlechildrens.org

 

Lab Genetic Counselor: LabGC@seattlechildrens.org

 

CPT Codes

Routine: 88230, 88262, 88291, 88280

 

Newborn (14 days old or less ONLY) or STAT request: 88230 (x2), 88262, 88291, 88280

 

Additional codes may be required for mosaic or limited studies, please contact Lab Client Services, 206-987-2617 or labclientservices@seattlechildrens.org

Methodology

Method: Standared G-band analysis of chromosomes

Requisition

Molecular Genetics & Cytogenetics Requisition

Clinical Utility

Chromosomes contain the thousands of genes in the human genome that direct cellular processes controlling growth, development, and functioning of the human body. Gains or losses in chromosome content lead to alterations in gene function and disrupt these vital cellular processes. This can result in intellectual disability or other developmental abnormalities, birth defects, and many well-characterized genetic syndromes.

This test will detect abnormalities in chromosome number, large chromosomal duplications and deletions and other large structural rearrangements.

Special Instructions

Test request form should be completed by the ordering physician.  For additional information or consultation call the Cytogenetics Lab at (206) 987-3961.  Evening and night shift: call the Clinical Lab at (206) 987-2102 or the on-call pathologist at (206) 987-2131.