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Structural variant analysis of outer chromosomal regions (quantitative measurement)

Published: August 9, 2026Updated: August 16, 2026

This test evaluates genetic changes in specific regions of chromosomes, often used to detect structural rearrangements like deletions, duplications, or translocations.

Quick summary

["Helps identify genetic variations that may influence health or disease risk."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
81301-4
Short code
Struct var outer start-end NumRange
Synonyms
Struct var outer start-end NumRange
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

What This Test Measures

Structural variants in the outer chromosomal arms (peripheral regions) are analyzed for size, location, and type of rearrangement. This may include balanced or unbalanced changes that affect gene dosage or function.

Why It’s Ordered

Doctors may request this test if you have symptoms suggestive of genetic disorders, a family history of chromosomal abnormalities, or if genetic counseling suggests a need for detailed chromosomal analysis beyond standard karyotyping.

Common Uses

Commonly used in prenatal testing, preimplantation genetic testing, or research to assess inherited or acquired chromosomal rearrangements that could impact health.

Sample Collection

Blood or other cellular samples are typically used. The test may involve isolating chromosomal material from cells for detailed structural analysis.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Frequently asked questions

How long will results take?
Results may take several weeks to months, depending on the complexity of the analysis and laboratory workflow.
What does a positive result mean?
A positive result indicates the presence of structural chromosomal changes. These findings may guide further testing, genetic counseling, or treatment planning, depending on clinical context.
Can this test detect all genetic disorders?
No, this test focuses specifically on structural variants in chromosomal arms. Other genetic tests (e.g., whole-genome sequencing, microarray analysis) may be needed for comprehensive genetic evaluation.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy