Lab Test

Peripheral Blood (Constitutional) Karyotype

Chromosome Testing, Karyotyping, Chromosome Analysis, Karyogram, Blood Karyotype, Chromosome Studies

Test Codes


Note: SNP chromosome microarray analysis should be considered prior to karyotype for any child with multiple congenital anomalies, (the pattern of which does not suggest a specific known genetic disorder), autism/autism spectrum disorder, developmental delay/intellectual disability, or seizures.


  • For newborn patients, please see Newborn Blood Karyotype.
  • Samples should be drawn as early in the day as possible so they can be delivered to the Laboratory the same day.
  • Clinical indications and tentative diagnosis must accompany any request for chromosome analysis. Also include name, age and sex of patient.
  • For further instructions or clarifications, contact the Cytogenetics Laboratory at Beaumont Hospital, Royal Oak: 248-551-9030 or 248-551-9029.

Specimen Collection Criteria

Collect: 6.0 mL whole blood (minimum: 3.0 mL) in a Dark Green-top Sodium Heparin tube (adults) or 1-2 mL whole blood (minimum: 1.0 mL) in a Dark Green-top Sodium Heparin tube (children).

  • Invert the tube several times to mix blood with the anticoagulant.
  • A copy of the requisition must be sent with the specimen.

Physician Office/Draw Specimen Preparation

If a specimen is obtained too late in the day to be delivered, it could be stored at room temperature (20-26°C or 68-78.8°F) or in a refrigerator (2-8°C or 36-46°F) and sent the next day. Do not heat or freeze the blood sample.

Preparation for Courier Transport

Transport: Whole blood, at room temperature (20-26°C or 68-78.8°F) or refrigerated (2-8°C or 36-46°F). (Minimum: 3.0 mL adult or 1.0 mL pediatric)

Rejection Criteria

  • Frozen specimens.
  • Clotted or hemolyzed specimens.
  • Specimens over 72 hours old.
  • Specimens drawn using an improper anticoagulant or were not maintained under sterile conditions. 

In-Lab Processing

Specimens are processed immediately upon receipt in the Laboratory.


Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 24 hours
Refrigerated (2-8°C or 36-46°F): 72 hours
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Refrigerated (2-8°C or 36-46°F): 7 days. A backup cell pellet is maintained for three weeks past sign-out of the final report.


Royal Oak Cytogenetics Laboratory


Monday – Friday, 8:00 am – 5:00 pm.
Results are available within 2 weeks.

Reference Range

Interpretation is provided with the report.

Test Methodology

Detailed G-banded chromosome analysis and written interpretation of the karyotype.

Special procedures: If the specimen requires special testing for microdeletions, subtelemeric deletions, cryptic rearrangements and other conditions that are not readily identifiable by G-banding or high resolution study, molecular cytogenetic study should be requested (FISH). Clinical indications and identification of a syndrome must be given for the application of specific molecular probes.

Clinical Utility

This test is used to evaluate congenital malformations, stillbirth, mental retardation, growth retardation, infertility, cryptorchidism, hypogonadism, amenorrhea (primary), abnormal/ambiguous genitalia, recurrent miscarriage, Turner syndrome, Klinefelter syndrome, Down syndrome, and other suspected chromosomal disorders.


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This directory currently reflects information only for specimens collected and/or processed at the
Farmington Hills, Grosse Pointe, Royal Oak, and Troy campuses.