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The Path to Diagnosis: Scoring and Genetic Testing

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Beckwith-Wiedemann Syndrome (BWS) is diagnosed using a clinical scoring system based on physical features, followed by genetic testing. Because BWS can involve mosaicism, a normal blood test does not rule out the condition, and testing other tissues like skin may be necessary for confirmation.

Key Takeaways

  • • A clinical score of 4 or more confirms a classic BWS diagnosis, while a score of 2 or more typically prompts genetic testing.
  • • Cardinal features of BWS include a large tongue, abdominal wall defects, and uneven body growth.
  • • Due to genetic mosaicism, a standard blood test may come back negative even if a child has BWS.
  • • Testing alternative tissues like skin or surgical samples can help confirm a diagnosis when blood tests are negative.
  • • Identifying the specific molecular subtype of BWS helps doctors create a personalized tumor screening and care plan.

Diagnosing Beckwith-Wiedemann Syndrome (BWS) has evolved. Because it is a “spectrum” disorder, doctors no longer rely on a simple “yes or no” list [1]. Instead, they use a sophisticated scoring system and advanced genetic testing to create a personalized care plan for your child [2][3].

The 2018 International Consensus Scoring System

To help doctors identify where a child sits on the spectrum, the 2018 International Consensus Statement created a clinical scoring system [2][4]. Symptoms are divided into two categories:

  • Cardinal Features (2 points each): These are the major signs, such as macroglossia (large tongue), omphalocele (abdominal wall defect), or lateralized overgrowth (one side of the body larger than the other) [5][6].
  • Suggestive Features (1 point each): These are minor or more common signs, such as neonatal hypoglycemia (low blood sugar at birth), ear creases/pits, or enlarged internal organs (like the liver or kidneys) [5][7].

What the Score Means

  • Score of 4 or more: This is considered a clinical diagnosis of classic BWS [8].
  • Score of 2 or more: This is the “threshold” where doctors typically recommend molecular (genetic) testing to confirm the diagnosis [2][9].

The Diagnostic Pathway: From Blood to Tissue

The first step in confirmation is usually a blood test to look for genetic changes on chromosome 11p15.5 [10]. However, this is where it can get tricky for parents.

Understanding Mosaicism

Many children with BWS have epigenetic mosaicism [11][12]. “Mosaicism” means that the genetic change is not present in every cell in the body [11]. It is like a mosaic tile floor where some tiles are one color (the BWS change) and others are a different color (normal cells) [12].

Because of this, a blood test may come back “normal” (negative) even if your child has BWS [11][12]. This happens because the blood cells might be the “normal” tiles, while the “BWS” tiles are located in other parts of the body, like the tongue, skin, or liver [13][11].

Why Further Testing Matters

If your child has a high clinical score but a negative blood test, your doctor may recommend testing a second tissue sample [13][14]. This might include:

  • A small skin sample (biopsy) [13].
  • A sample of tissue from a tongue reduction or umbilical cord repair surgery [13][11].

Confirming the diagnosis through these other tissues is vital because it helps identify the specific molecular subtype [15]. This “subtype” is the blueprint that tells your medical team exactly which tumors to look for and how often to screen for them [10][15]. Knowing the molecular cause provides the most accurate roadmap for your child’s long-term health [15][3].

Frequently Asked Questions

What clinical score is needed to diagnose Beckwith-Wiedemann Syndrome?
A clinical score of 4 or more is considered a clinical diagnosis of classic BWS. If a child has a score of 2 or more, doctors typically recommend genetic testing to confirm the diagnosis.
Why might a BWS blood test come back normal even if my child has symptoms?
This can happen due to a condition called mosaicism, where the genetic change is only present in certain cells. The blood cells might be normal, while the genetic changes causing BWS are located in other tissues like the skin, liver, or tongue.
What are the cardinal features of Beckwith-Wiedemann Syndrome?
Cardinal features are major signs of BWS that score two points each in the diagnostic system. These include a large tongue (macroglossia), an abdominal wall defect (omphalocele), and one side of the body growing larger than the other (lateralized overgrowth).
If a blood test is negative for BWS, what is the next step?
If a child has a high clinical score but a negative blood test, doctors often recommend testing a second tissue sample. This can involve a small skin biopsy or testing tissue collected during a surgery, which may reveal genetic changes missed by the initial blood test.

Questions for Your Doctor

  • • What is my child's total score on the 2018 International Consensus clinical scoring system?
  • • If my child's blood test was negative, does that completely rule out BWS, or should we consider testing another tissue?
  • • Is my child's current screening schedule based on their clinical score or a confirmed molecular subtype?
  • • Because of the possibility of mosaicism, which tissue (skin, tongue, etc.) would be most reliable to test next if the blood test was normal?
  • • How does a 'classic' BWS diagnosis (score of 4+) change our immediate next steps compared to a lower score?

Questions for You

  • • What physical signs did I first notice in my child (e.g., a large tongue, an umbilical hernia, or uneven growth)?
  • • Has my child had any low blood sugar episodes, and were these counted toward their clinical score?
  • • Am I comfortable advocating for further tissue testing if the blood test is negative but my child still has many features of BWS?

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References

  1. 1

    Characterization of the Beckwith-Wiedemann spectrum: Diagnosis and management.

    Duffy KA, Cielo CM, Cohen JL, et al.

    American journal of medical genetics. Part C, Seminars in medical genetics 2019; (181(4)):693-708 doi:10.1002/ajmg.c.31740.

    PMID: 31469230
  2. 2

    [Beckwith-Wiedemann Syndrome (BWS) Current Status of Diagnosis and Clinical Management: Summary of the First International Consensus Statement].

    Elbracht M, Prawitt D, Nemetschek R, et al.

    Klinische Padiatrie 2018; (230(3)):151-159 doi:10.1055/a-0591-9479.

    PMID: 29660755
  3. 3

    (Epi)genotype-phenotype correlations in Beckwith-Wiedemann syndrome: a paradigm for genomic medicine.

    Mussa A, Russo S, Larizza L, et al.

    Clinical genetics 2016; (89(4)):403-415 doi:10.1111/cge.12635.

    PMID: 26138266
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    Beckwith-Wiedemann spectrum (BWSp): an update on diagnosis, management, and follow-up from the scientific committee of the Italian BWSp association.

    Russo S, Milani D, Meossi C, et al.

    Italian journal of pediatrics 2025; (51(1)):287 doi:10.1186/s13052-025-02131-3.

    PMID: 41126215
  5. 5

    Introduction to the Beckwith-Wiedemann Syndrome and Cancer Special Issue.

    Mussa A, Kalish JM

    Cancers 2023; (15(20)) doi:10.3390/cancers15204939.

    PMID: 37894306
  6. 6

    Clinical and molecular features of children with Beckwith-Wiedemann syndrome in China: a single-center retrospective cohort study.

    Wang R, Xiao Y, Li D, et al.

    Italian journal of pediatrics 2020; (46(1)):55 doi:10.1186/s13052-020-0819-3.

    PMID: 32349794
  7. 7

    Clinical and Molecular Evaluation of Beckwith-Wiedemann Syndrome with the BWSICS Score.

    Çetinkaya D, Altan M, Kılıç E

    Molecular syndromology 2025; (16(5)):436-441 doi:10.1159/000543374.

    PMID: 41230207
  8. 8

    Multi-locus methylation analyses reveal GNAS methylation defects in three patients with the Beckwith-Wiedemann syndrome phenotype and no molecular defects in the 11p15.5 imprinted region.

    Urakawa T, Kanamaru Y, Amano N, et al.

    Clinical epigenetics 2025; (17(1)):97 doi:10.1186/s13148-025-01907-y.

    PMID: 40490796
  9. 9

    Performance Metrics of the Scoring System for the Diagnosis of the Beckwith-Wiedemann Spectrum (BWSp) and Its Correlation with Cancer Development.

    Luca M, Carli D, Cardaropoli S, et al.

    Cancers 2023; (15(3)) doi:10.3390/cancers15030773.

    PMID: 36765732
  10. 10

    Expert consensus document: Clinical and molecular diagnosis, screening and management of Beckwith-Wiedemann syndrome: an international consensus statement.

    Brioude F, Kalish JM, Mussa A, et al.

    Nature reviews. Endocrinology 2018; (14(4)):229-249 doi:10.1038/nrendo.2017.166.

    PMID: 29377879
  11. 11

    Somatic Mosaicism for Paternal Uniparental Disomy of 11p15.5 Region in Adrenal and Liver Tissues in a Newborn with Atypical Beckwith-Wiedemann Syndrome.

    Urzua A, Burattini S, Pinochet C, et al.

    Journal of pediatric genetics 2019; (8(4)):226-230 doi:10.1055/s-0039-1692197.

    PMID: 31687262
  12. 12

    Coexistence of paternally-inherited ABCC8 mutation and mosaic paternal uniparental disomy 11p hyperinsulinism.

    Tung JY, Lai SHY, Au SLK, et al.

    International journal of pediatric endocrinology 2020; (2020()):13 doi:10.1186/s13633-020-00083-5.

    PMID: 32670376
  13. 13

    Improved molecular detection of mosaicism in Beckwith-Wiedemann Syndrome.

    Baker SW, Duffy KA, Richards-Yutz J, et al.

    Journal of medical genetics 2021; (58(3)):178-184 doi:10.1136/jmedgenet-2019-106498.

    PMID: 32430359
  14. 14

    Characteristics Associated with Tumor Development in Individuals Diagnosed with Beckwith-Wiedemann Spectrum: Novel Tumor-(epi)Genotype-Phenotype Associations in the BWSp Population.

    Duffy KA, Getz KD, Hathaway ER, et al.

    Genes 2021; (12(11)) doi:10.3390/genes12111839.

    PMID: 34828445
  15. 15

    Molecular Basis of Beckwith-Wiedemann Syndrome Spectrum with Associated Tumors and Consequences for Clinical Practice.

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    Cancers 2022; (14(13)) doi:10.3390/cancers14133083.

    PMID: 35804856

This page explains Beckwith-Wiedemann Syndrome diagnostic scoring and genetic testing for educational purposes. Always consult a pediatric geneticist or your child's medical team for a formal diagnosis and tailored testing plan.

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