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Genetic Test for Prenatal or Congenital Prader-Willi Syndrome (PWS) or Angelman Syndrome (AS) Using Sheep Blood DNA Extraction and Next-Generation Sequencing

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

This test checks for genetic changes linked to Prader-Willi Syndrome (PWS) or Angelman Syndrome (AS) using DNA from your baby’s blood. These conditions can affect growth, behavior, and development.

Quick summary

["Early genetic screening helps identify potential genetic disorders before symptoms appear."]

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

Key facts at a glance

LOINC
76415-9
Short code
Sheep PrP codon 154 Bld Genotyp
Synonyms
Sheep PrP codon 154 Bld Genotyp
Category
chemistry
Sample
whole-blood
Container
Lavender-top (EDTA)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
genotyping
Specimen volume
3 mL
Stability
Room temperature: 4h, Refrigerated: 24h
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

What Is Prader-Willi Syndrome (PWS) or Angelman Syndrome (AS)?

Prader-Willi Syndrome (PWS) and Angelman Syndrome (AS) are rare genetic disorders caused by changes in a specific chromosome region. PWS often leads to challenges with feeding, growth delays, and behavioral issues, while AS may cause speech difficulties, seizures, and developmental delays. Both can impact learning and daily functioning.

How Is This Test Performed?

A small amount of your baby’s blood is collected, usually from the heel, and sent to a lab. The DNA is extracted and analyzed to check for specific genetic markers associated with PWS or AS.

Why Might This Test Be Ordered?

Your healthcare provider may recommend this test if you have a family history of PWS or AS, if you’re pregnant, or if your baby shows early signs of developmental delays or feeding difficulties.

What Are the Possible Results?

Results can be normal (no genetic changes detected) or abnormal (indicating a possible PWS or AS). Abnormal results will be reviewed by a genetic counselor or specialist for further evaluation.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance: Early Detection and Support

Short name

PWS/AS Genetic Screening

Frequently asked questions

What does a positive result mean?
A positive result suggests a higher likelihood of PWS or AS, which can guide early interventions, specialized care, and support for your baby’s development. Genetic counseling is essential to discuss next steps.
What if the test is negative?
A negative result means no obvious genetic changes were found for PWS or AS in this test. However, other genetic or medical conditions could still be causing symptoms. Follow-up with your healthcare provider is important.
How soon will I get my results?
Results typically take 2–4 weeks. Your healthcare provider will coordinate with the lab to share findings and next steps, often with genetic counseling support.
  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