Beckwith-Wiedemann syndrome (BWS) is an overgrowth condition that affects specific chromosomes in a fetus. It can cause certain body parts to grow too much in a baby or child.

The condition affects many different areas of the body and can cause a baby or child to be significantly larger than their peers. The overgrowth usually tapers off around the age of 8 years, resulting in the person having an average adult height.

Depending on the affected areas, the person may display various signs and symptoms. The underlying cause of the condition may also vary depending on which genes the condition affects.

It is important to work with a doctor in each case of BWS to help identify any risk factors early on, as people with the condition may be more at risk for some types of cancer and other health issues.

However, most children with BWS lead normal lives.

Keep reading to learn more about the causes, symptoms, and treatment of Beckwith-Wiedemann syndrome.

Doctor checking for Beckwith-Wiedemann syndromeShare on Pinterest
Image credit: Klaus Tiedge / Getty Images.

The causes of BWS are complex. The condition generally results from the abnormal regulation of genes on chromosome 11.

Changes in a specific region called 11p15 are responsible for most cases of BWS. For the most part, these genetic changes occur in a large majority of a person’s cells. Scientists refer to this as mosaicism, meaning that there is a mixture of both healthy cells and cells with this altered genetic expression.

This mosaicism leads to the wide variety of symptoms and features in people with BWS. There are a few different variations in these genetic expressions.

Possible genetic alterations include:

Abnormal methylation

Methylation is a chemical reaction that attaches certain methyl groups to the DNA of the cells. Abnormal methylation disrupts the regulation of certain genes, which can lead to abnormal growth, as occurs in cases of BWS. The National Library of Medicine (NLM) note that this process causes at least half of all cases of BWS.

Paternal uniparental disomy (UPD)

Paternal UPD causes a person to have two copies of inherited genes from the father rather than one copy from each parent. It causes about 20% of cases of BWS.

Mutations in the CDKN1C gene

The CDKN1C gene helps create a protein that limits growth in the cells. Mutations in this gene are less common than other causes, but they prevent the limitation of growth, leading to symptoms of BWS.

Chromosomal abnormalities

In rare cases, abnormalities in chromosome 11 — such as the translocation, duplication, or deletion of genetic material from the chromosome — can also lead to symptoms of BWS.

Is it inherited?

Although the condition involves the genes, this does not mean that it automatically passes from parent to child.

According to experts, in about 85% of cases, the individual has no family history of BWS. Only about 15% of affected people have a family history of the condition.

There is a chance that the parents of an affected child may have another child with the condition, depending on the underlying genetic cause. While some parents have only a 1% chance of having another child with the condition, the likelihood for other parents may be as high as 50%.

Parents of a child with BWS should contact a gene specialist to determine the cause and individual risk factors.

The medical community considers BWS to be a spectrum disorder. People with the condition may present with signs or symptoms ranging from mild to more severe. These include:

  • large tongue
  • large body size
  • overgrowth on one side of the body
  • high or low birth weight
  • pink or red facial birthmarks
  • creases or pits in the ears
  • enlarged organs, such as the liver or kidney
  • abdominal wall abnormalities, such as umbilical hernia
  • high or low blood sugar
  • cleft palate
  • cardiomyopathy

People with BWS may also be more at risk for some rare tumors, including:

The NLM note that tumors develop in about 10% of people and almost always appear during childhood.

The diagnosis of BWS is relatively rare, with the condition affecting 1 in 10,500 to 13,700 newborns worldwide. However, BWS may be more common than this because many people with mild symptoms never receive a diagnosis.

Additionally, fully diagnosing a genetic condition can be challenging. A full diagnosis involves many steps, including:

  • physical examination
  • medical history
  • family history
  • laboratory testing

To diagnose the syndrome, doctors may analyze DNA from both the child and parents. Anyone interested in genetic testing should ask their doctor for a referral to a genetic specialist.

Treatment for BWS centers on treating any common symptoms and complications from the condition.

For example, doctors will monitor infants for low blood sugar and increase feeding frequency or administer glucose to bring the ranges within normal.

Babies with an overgrowth of the tongue (macroglossia) may have difficulty breathing, swallowing, and speaking. Although macroglossia does not require treatment in many cases, some infants will require a visit to a specialist to explore the available options.

A specialist may recommend removing part of the tongue to help the rest of the mouth grow normally if necessary.

Children with abdominal wall abnormalities may require surgical treatment to keep the internal organs safe and prevent life threatening complications.

Continual surveillance is an important part of the treatment for BWS and its complications. Doctors may recommend regular abdominal ultrasounds to check for abnormalities and tumors.

Children who develop growths and tumors will need additional evaluation by a specialist.

Specialists can also help identify any growth-related abnormalities and correct them if necessary as the child grows.

There is no known prevention for BWS. People who have a child with BWS and are looking to have more children may wish to consider genetic counseling to explore their options.

The majority of children with BWS lead normal lives. In most cases, there are no serious medical problems associated with the condition.

Additionally, BWS does not usually affect a person’s life expectancy.

BWS is an overgrowth condition affecting specific genes in the body.

There may sometimes be a genetic factor to the condition, though this is not always the case.

Babies and children with BWS may have various signs and symptoms of the condition. They are also at risk for some more severe conditions, such as kidney issues and some types of tumors.