A plain-language guide

Beckwith-Wiedemann syndrome

What's known, what's still uncertain, and what's actively debated, written plainly, and built only from published medical research.

Growing map · 39 sourced statements Every statement names its source Updated 2026-08-04
Please read this first. This guide is a companion to your medical team, not a replacement, and it is not medical advice. Everything here is tied to published research. If something you expected is not here, it almost always means we have not mapped a source for it yet, not that it is unknown to medicine. Beckwith-Wiedemann syndrome is an early, growing map, so it will look incomplete on purpose: we would rather show less and have every line be something you can check than fill the page with claims we cannot stand behind. For anything about your own situation, your clinicians hold the full picture. How this guide is built and why.

What's Beckwith-Wiedemann syndrome?

Beckwith-Wiedemann syndrome is a congenital overgrowth disorder that arises from genetic and epigenetic changes at the imprinted 11p15.5 region. It typically involves overgrowth, a large tongue, abdominal wall defects, low blood sugar in the newborn period, and an increased risk of certain childhood tumors.

Also indexed asOMIM:130650, MONDO:0007534
Features mapped15
Treatments mapped6
Published sources10
Last reviewed2026-08-04

Signs and symptoms

Hemihypertrophy

Beckwith-Wiedemann syndrome is one of the conditions characterised by lateralized overgrowth, where one part or side of the body grows larger than the other.

Limited evidenceSource: PMID:40949896
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:33392121, OMIM:130650
Notesplain_language confirmed from PMID:33392121 via curation 2026-06-25 [claude-draft]. | regrounded primary OMIM:130650 -> PMID:40949896 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Placental mesenchymal dysplasia

Placental mesenchymal dysplasia (PMD) is a rare condition affecting the placenta that can look very similar to certain pregnancy-related growth disorders on ultrasound scans.

Limited evidenceSource: PMID:36428656
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:39848073, OMIM:130650
Notesplain_language confirmed from PMID:39848073 via curation 2026-06-13. | regrounded primary OMIM:130650 -> PMID:36428656 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Overgrowth

Beckwith-Wiedemann syndrome is a congenital overgrowth disorder, meaning the body or parts of it grow larger than usual, driven by genetic and epigenetic changes at the 11p15.5 region of chromosome 11.

Limited evidenceSource: PMID:42158694
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:42074571, OMIM:130650
Notesplain_language confirmed from PMID:42074571 via curation 2026-06-13. plain_language confirmed from PMID:42158694 via curation 2026-06-25 [claude-draft]. | regrounded primary OMIM:130650 -> PMID:42158694 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Nevus flammeus

A facial nevus flammeus, commonly called a port-wine stain, is a flat reddish birthmark that can appear in Beckwith-Wiedemann syndrome, often on the forehead or eyelids. It is one of the suggestive features of the condition.

Limited evidenceSource: PMID:40949896
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesOMIM:130650
Notesplain_language confirmed from PMID:40949896 via curation 2026-06-26 [claude-draft]. | regrounded primary OMIM:130650 -> PMID:40949896 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Hepatoblastoma

There is an increased risk of hepatoblastoma, a childhood liver tumor. Screening with blood tests and ultrasound aims to catch it early.

Limited evidenceSource: PMID:42158694
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesOMIM:130650
Notesplain_language confirmed from PMID:42158694 via curation 2026-06-13. | regrounded primary OMIM:130650 -> PMID:42158694 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Nephroblastoma

There is an increased risk of Wilms tumor (nephroblastoma), a childhood kidney tumor. This is why regular tumor screening is recommended in early childhood.

Limited evidenceSource: PMID:42158694
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesOMIM:130650
Notesplain_language confirmed from PMID:42158694 via curation 2026-06-13. | regrounded primary OMIM:130650 -> PMID:42158694 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Omphalocele

An abdominal wall defect such as an omphalocele, where abdominal contents protrude through the navel, can be present at birth and is repaired surgically.

Limited evidenceSource: PMID:42158694
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesOMIM:130650
Notesplain_language confirmed from PMID:42158694 via curation 2026-06-13. | regrounded primary OMIM:130650 -> PMID:42158694 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Neonatal hypoglycemia

Low blood sugar in the newborn period (often from excess insulin) is common and can be persistent, so monitoring and treatment in early life matter.

Limited evidenceSource: PMID:42158694
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesOMIM:130650
Notesplain_language confirmed from PMID:42158694 via curation 2026-06-13. | regrounded primary OMIM:130650 -> PMID:42158694 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Enlarged kidney

Enlarged kidneys (nephromegaly) can occur in Beckwith-Wiedemann syndrome as part of its overgrowth pattern. It is one of the suggestive features that can prompt evaluation for the condition.

Limited evidenceSource: PMID:40949896
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesOMIM:130650
Notesplain_language confirmed from PMID:40949896 via curation 2026-06-26 [claude-draft]. | regrounded primary OMIM:130650 -> PMID:40949896 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Kidney stone

Some people with medullary sponge kidney (MSK) have no symptoms at all, while others may experience blood in the urine, pain from kidney stones, repeated urinary tract infections, or problems with the body’s chemical balance.

Limited evidenceCurated reference: OMIM:130650
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:40287601
Notesplain_language confirmed from PMID:40287601 via curation 2026-06-13.
Last reviewed2026-06-13

Hepatomegaly

An enlarged liver (hepatomegaly) can occur in Beckwith-Wiedemann syndrome, where it is described as a suggestive feature seen in a minority of children.

Limited evidenceSource: PMID:40949896
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesOMIM:130650
Notesplain_language confirmed from PMID:40949896 via curation 2026-06-26 [claude-draft]. | regrounded primary OMIM:130650 -> PMID:40949896 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Macroglossia

Macroglossia, an enlarged tongue, is a frequent feature of Beckwith-Wiedemann syndrome. It can affect breathing, feeding, speech, and the developing jaw and teeth.

Limited evidenceSource: PMID:39774467
Evidence ratingweak
Study designontology_import
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:42158694, OMIM:130650
Notesplain_language confirmed from PMID:42158694 via curation 2026-06-13. plain_language confirmed from PMID:39774467 via curation 2026-06-25 [claude-draft]. | regrounded primary OMIM:130650 -> PMID:39774467 on 2026-06-26 [Carrie Schluter, BCPA]
Last reviewed2026-06-26

Macrosomia (overgrowth at birth)

Babies with Beckwith-Wiedemann are often unusually large at birth and grow faster than expected in early childhood (macrosomia). This generalized overgrowth is one of the core features that prompts testing for the syndrome.

Limited evidenceSource: PMID:42158694
Evidence ratingweak
Study designreview
Confidence (0-1)0.7
Replicationunreplicated
Notesplain_language confirmed from PMID:42158694 via curation 2026-06-18 [carrie (curation)].
Last reviewed2026-06-18

Organomegaly (visceromegaly)

Internal organs such as the liver, kidneys, and spleen can be enlarged in Beckwith-Wiedemann (organomegaly). This enlargement reflects the same overgrowth process that affects the rest of the body.

Limited evidenceSource: PMID:42158694
Evidence ratingweak
Study designreview
Confidence (0-1)0.7
Replicationunreplicated
Supporting sourcesPMID:27650505
Notesplain_language confirmed from PMID:27650505 via curation 2026-06-18 [carrie (curation)].
Last reviewed2026-06-18

Hyperinsulinism

Many newborns with Beckwith-Wiedemann make too much insulin (hyperinsulinism), which drives blood sugar dangerously low in the first days of life. Recognizing and treating this is a key part of early care.

Limited evidenceSource: PMID:42158694
Evidence ratingweak
Study designreview
Confidence (0-1)0.7
Replicationunreplicated
Notesplain_language confirmed from PMID:42158694 via curation 2026-06-18 [carrie (curation)].
Last reviewed2026-06-18

How it is diagnosed

Beckwith-Wiedemann syndrome

Diagnosed using: 11p15.5 methylation and uniparental disomy testing.

Limited evidenceSource: PMID:42158694
The source text this rests on
“…including methylation-specific testing and uniparental disomy…”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:42158694 via curation 2026-06-25
Last reviewed2026-06-25

Beckwith-Wiedemann syndrome

Diagnosed using: tumor surveillance with abdominal ultrasound and serum AFP.

Limited evidenceSource: PMID:42158694
The source text this rests on
“Long-term care emphasizes structured tumor screening [abdominal ultrasound and serum alpha-fetoprotein (AFP)], growth and developmental monitoring, functional rehabilitation, and genetic counseling to address familial recurrence risks.”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:42158694 via curation 2026-06-26
Last reviewed2026-06-26

Treatment and management

What the research describes, not a recommendation. Treatment decisions belong with your clinician.

This covers treatments that appear in the published research mapped here. Investigational and experimental therapies are not included, so their absence is a boundary of this map, not a sign they do not exist.

tumor surveillance

Because of the raised tumor risk, long-term care centers on structured tumor screening, typically abdominal ultrasound and a blood test for alpha-fetoprotein, alongside growth and developmental monitoring. The aim is early detection, not cure; the right schedule for any child is set with their care team.

Used to help with: Beckwith-Wiedemann syndrome.

Limited evidenceSource: PMID:42158694
The source text this rests on
“Long-term care emphasizes structured tumor screening [abdominal ultrasound and serum alpha-fetoprotein (AFP)], growth and developmental monitoring, functional rehabilitation, and genetic counseling to address familial recurrence risks.”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:42158694 via curation 2026-06-13
Last reviewed2026-06-13

tongue reduction surgery

Partial glossectomy (tongue reduction surgery) is a common procedure used in Beckwith-Wiedemann syndrome to reduce problems caused by an enlarged tongue, such as difficulties with breathing, feeding, and speech.

Used to help with: Beckwith-Wiedemann syndrome.

Limited evidenceSource: PMID:39774467
The source text this rests on
“Macroglossia is a frequent clinical feature of Beckwith-Wiedemann syndrome (BWS), a congenital overgrowth disorder. Macroglossia can lead to abnormal breathing, feeding, speech, and dentoskeletal development. Partial glossectomy is a common intervention aimed at reducing these abnormalities.”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:39774467 via curation 2026-06-25
Last reviewed2026-06-25

diazoxide

Diazoxide is a medication used to manage the hyperinsulinism-driven low blood sugar of Beckwith-Wiedemann syndrome; in a cohort of children, some required a course of diazoxide therapy lasting up to several months.

Used to help with: Beckwith-Wiedemann syndrome.

Limited evidenceSource: PMID:24468603
The source text this rests on
“10 patients had no HH, 5 had mild transient HH that resolved spontaneously, and 4 required diazoxide therapy for up to 6…”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:24468603 via curation 2026-06-26
Last reviewed2026-06-26

octreotide

Octreotide, a somatostatin analog, is used to help control the low blood sugar of hyperinsulinism in Beckwith-Wiedemann syndrome, typically when the low blood sugar does not respond to first-line medication.

Used to help with: Beckwith-Wiedemann syndrome.

Limited evidenceSource: PMID:26867223
The source text this rests on
“Octreotide, a somatostatin analog, often has a role in the management of these…”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:26867223 via curation 2026-06-26
Last reviewed2026-06-26

omphalocele surgical repair

In Beckwith-Wiedemann syndrome, an abdominal wall defect such as omphalocele is repaired using standard surgical approaches in the newborn period.

Used to help with: Beckwith-Wiedemann syndrome.

Limited evidenceSource: PMID:42158694
The source text this rests on
“Meanwhile, omphalocele is addressed following standard surgical management approaches.”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:42158694 via curation 2026-06-26
Last reviewed2026-06-26

continuous glucose monitoring

Continuous glucose monitoring is used in the newborn period in Beckwith-Wiedemann syndrome to track and manage the low blood sugar that can result from hyperinsulinism.

Used to help with: Beckwith-Wiedemann syndrome.

Limited evidenceSource: PMID:42158694
The source text this rests on
“…critical issues such as hypoglycemia due to hyperinsulinism and airway compromise from macroglossia require specialized interventions [e.g., continuous glucose monitoring (CGM) and tongue-reduction…”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:42158694 via curation 2026-06-26
Last reviewed2026-06-26

What changes how it shows up

Carrying the genetic change is not the whole story. The factors below are described in the research mapped here as changing whether, or how strongly, the condition appears. They modulate how the genotype is expressed; they do not, on their own, cause or cure it.

11p15.5 imprinting alteration

Most cases of Beckwith-Wiedemann syndrome trace to a change at the imprinting control regions IC2 and IC1 on chromosome 11p15.5: loss or gain of methylation, paternal uniparental disomy of 11p15, or a change in the CDKN1C gene. Which change is present helps explain the features and tumor risk.

Described as modulating: Beckwith-Wiedemann syndrome.

Limited evidenceSource: PMID:41126215
The source text this rests on
“The disorder is primarily associated with loss or gain of methylation at imprinting control regions IC2 and IC1, paternal uniparental disomy of 11p15, or pathogenic variants in CDKN1C.”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:41126215 via curation 2026-06-25
Last reviewed2026-06-25

telomeric vs centromeric imprinting domain

The molecular changes in Beckwith-Wiedemann syndrome fall in two imprinting domains on chromosome 11p15: a telomeric domain (with the H19 and IGF2 genes) and a centromeric domain (with the KCNQ1OT1 and CDKN1C genes). Changes in the telomeric domain are associated with overgrowth and cancer predisposition.

Described as modulating: Beckwith-Wiedemann syndrome.

Limited evidenceSource: PMID:11751681
The source text this rests on
“…disorders of imprinting in the telomeric domain are associated with overgrowth and cancer predisposition, whereas those in the centromeric domain involve malformations but not tumor…”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:11751681 via curation 2026-06-25
Last reviewed2026-06-25

paternal uniparental disomy 11p15 hyperinsulinism severity

When Beckwith-Wiedemann syndrome is caused by paternal uniparental disomy of chromosome 11p15, the hyperinsulinism tends to be more persistent and severe than in other molecular subgroups, where the low blood sugar is more often transient.

Described as modulating: Beckwith-Wiedemann syndrome.

Limited evidenceSource: PMID:26545876
The source text this rests on
“We found that patients with pUPD11p-associated HI have a persistent and severe HI phenotype compared with transient hypoglycaemia of BWS/11p overgrowth patients caused by other aetiologies.”
An excerpt quoted verbatim from the source named above, shown as recorded. The full sentence is in the linked source.
Evidence ratingweak
Confidence (0-1)0.7
Replicationunreplicated
Notesconfirmed from PMID:26545876 via curation 2026-06-26
Last reviewed2026-06-26

How to read the evidence labels

Widely acceptedSpecialists broadly agree on this.
Strong evidenceBacked by solid, repeated research.
Moderate evidenceReasonable evidence, still being confirmed.
Limited evidenceSome evidence, but not yet convincing.
Early evidenceAn early finding that needs more study.
Experts disagreeResearchers actively disagree about this.
No longer supportedLater, stronger evidence or guidance overturned this.

Where this comes from

This guide is built from 10 published source(s). Every claim above links back to one of them. Click any source ID to read the original on PubMed.

OMIM:130650 · Orphanet/HPO annotations for Beckwith-Wiedemann syndrome
PMID:11751681 · Tumor development in the Beckwith-Wiedemann syndrome is associated with a variety of constitutional molecular 11p15 alte
PMID:24468603 · The heterogeneity of hyperinsulinaemic hypoglycaemia in 19 patients with Beckwith-Wiedemann syndrome due to KvDMR1 hypom
PMID:26545876 · Congenital hyperinsulinism in children with paternal 11p uniparental isodisomy and Beckwith-Wiedemann syndrome.
PMID:26867223 · Late Presentation of Fulminant Necrotizing Enterocolitis in a Child with Hyperinsulinism on Octreotide Therapy.
PMID:36428656 · Placental Mesenchymal Dysplasia and Beckwith-Wiedemann Syndrome.
PMID:39774467 · Outcomes of Tongue Reduction Surgery in Beckwith-Wiedemann Syndrome: A Systematic Review.
PMID:40949896 · Clinical phenotype and molecular genetic analysis of 24 cases of Beckwith-Wiedemann syndrome.
PMID:41126215 · Beckwith-Wiedemann spectrum (BWSp): an update on diagnosis, management, and follow-up from the scientific committee of t
PMID:42158694 · Recent advances in neonatal Beckwith-Wiedemann syndrome: from molecular diagnosis to multidisciplinary management-a narrative review.

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