G-Banded Chromosome Analysis
GTR Test Accession: Help GTR000520908.7
Last updated in GTR: 2023-12-11
Last annual review date for the lab: 2023-09-26 LinkOut
At a Glance
Diagnosis; Recurrence; Risk Assessment
Advanced maternal age gravida; Anomaly of sex chromosome; Autosomal chromosomal disorder; ...
Chromosome 13; Chromosome 18; Chromosome 21; Human genome; Sex chromosome X; ...
Cytogenetics - Karyotyping: G-banding
Individuals with a personal or family history of infertility or …
G-banded chromosome analysis will detect polyploidies, aneuploidies, large balanced alterations …
Establish or confirm diagnosis; Reproductive decision-making
Ordering Information
Offered by: Help
Specimen Source: Help
  • Amniocytes
  • Amniotic fluid
  • Bone marrow
  • Cell culture
  • Chorionic villi
  • Cord blood
  • Fetal blood
  • Fibroblasts
  • Fresh tissue
  • Peripheral (whole) blood
  • Product of conception (POC)
  • Skin
  • View specimen requirements
Who can order: Help
  • Genetic Counselor
  • Health Care Provider
  • Licensed Dentist
  • Licensed Physician
  • Nurse Practitioner
  • Physician Assistant
  • Registered Nurse
Lab contact: Help
Whitney Neufeld-Kaiser, MS, Certified Genetic counselor, CGC, Genetic Counselor
Contact Policy: Help
Laboratory can only accept contact from health care providers. Patients/families are encouraged to discuss genetic testing options with their health care provider.
How to Order: Help
The requisition is found under the how to order URL. We are able to receive specimens 24 hours a day, 7 days a week. Please call the lab at 206-598-4488 for further information.
Order URL
Test service: Help
Clinical Testing/Confirmation of Mutations Identified Previously
Confirmation of research findings
Custom Balanced Chromosome Rearrangement Studies
Marker Chromosome Identification
Result interpretation
X-Chromosome Inactivation Studies
Test additional service: Help
Custom Prenatal Testing
Test development: Help
Test developed by laboratory (no manufacturer test name)
Informed consent required: Help
Test strategy: Help
Consider reflex testing to cytogenomic microarray analysis when chromosome analysis is normal in a child being evaluated for a recognized aneuploidy syndrome.
Pre-test genetic counseling required: Help
Post-test genetic counseling required: Help
Recommended fields not provided:
Conditions Help
Total conditions: 16
Condition/Phenotype Identifier
Test Targets
Chromosomal regions/Mitochondria Help
Total chromosomal regions/mitochondria: 6
Chromosomal region/Mitochondrion Associated condition
Total methods: 1
Method Category Help
Test method Help
Instrument *
* Instrument: Not provided
Clinical Information
Test purpose: Help
Diagnosis; Recurrence; Risk Assessment
Clinical validity: Help
G-banded chromosome analysis will detect polyploidies, aneuploidies, large balanced alterations (i.e. reciprocal translocations, Robertsonian translocations, inversions, balanced insertions), and large unbalanced translocations, duplications and deletions.
Clinical utility: Help
Establish or confirm diagnosis
View citations (1)
  • Laboratory guideline for Turner syndrome. Wolff DJ, et al. Genet Med. 2010;12(1):52-5. doi:10.1097/GIM.0b013e3181c684b2. PMID: 20081420.

Reproductive decision-making

Target population: Help
Individuals with a personal or family history of infertility or 2 or more unexplained pregnancy losses; individuals with features consistent with aneuploidy syndromes, such as Down syndrome, Klinefelter syndrome, or Turner syndrome; individuals with a family history of an aneuploidy syndrome or chromosome rearrangement (for example a translocation or an … View more
Variant Interpretation:
What is the protocol for interpreting a variation as a VUS? Help
Parental chromosome analysis is requested when a rare polymorphism is detected in the proband.

Are family members with defined clinical status recruited to assess significance of VUS without charge? Help

Will the lab re-contact the ordering physician if variant interpretation changes? Help
Is research allowed on the sample after clinical testing is complete? Help
Sample reports:
Sample Positive Report Help
Sample Positive Report
Recommended fields not provided:
Technical Information
Availability: Help
Tests performed
Entire test performed in-house
Analytical Validity: Help
Band resolution of 450-850
Assay limitations: Help
The standard cytogenetic methodology used in this analysis does not routinely detect subtle rearrangements, low-level mosaicism (note that screening of additional cells can be ordered if mosaicism is suspected), or microdeletions and microduplications below the resolution of the banding level. This test will not detect either point mutations or DNA … View more
Proficiency testing (PT):
Is proficiency testing performed for this test? Help

Method used for proficiency testing: Help
Formal PT program

PT Provider: Help
American College of Medical Genetics / College of American Pathologists, ACMG/CAP

Description of PT method: Help
As part of CAP accreditation, proficiency testing is performed three times per year. The laboratory is provided with approximately a dozen constitutional unknown specimens for testing each year, and results are returned to CAP for evaluation. The UW Cytogenetics and Genomics Laboratory has consistently participated and successfully identified the expected … View more
Recommended fields not provided:
Regulatory Approval
FDA Review: Help
Category: Not Applicable
Additional Information

IMPORTANT NOTE: NIH does not independently verify information submitted to GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.