Authors: Praveen Kumar Ramani, MBBS, University of Arkansas/Arkansas Children’s Hospital 
Sonika Agarwal, MBBS, MD, Children’s Hospital of Philadelphia  

Reviewed: September 2022

SUMMARY

Williams syndrome is also known as Williams-Beuren syndrome or Happy Syndrome. It’s a rare genetic disorder. It involves:  

• The heart 
• The brain 
• Intellectual and learning differences
• Abnormal calcium levels 
• Distinct facial features 
• Impact on connective tissue and growth
• Social and behavioral differences 

Williams syndrome can occur spontaneously due to a genetic change. Specifically, a region in chromosome 7 has a missing piece. This region is 7q11.23.  

Patients usually have a normal life expectancy. Some patients may have a reduced life expectancy. This is due to complications related to the heart and kidney.  

There is no cure for Williams syndrome. Symptoms can present at birth. They can also develop as a child grows older. Patients often need supportive care as they become adults.

Disorder Overview

DESCRIPTION

Williams syndrome occurs in both sexes. One in every 10,000 to 20,000 babies born in the United States has this condition.  

Symptoms can vary widely among patients. They can be mild or more severe. Some common ones include: 

• Medical concerns 
• Emotional issues 
• Anxiety 
• Learning differences   
• Hypersociability: (outgoing, very social and friendly even to strangers)

SIGNS AND SYMPTOMS

Most patients with Williams syndrome are diagnosed as a newborn or in early childhood. The average age of diagnosis is around three and a half years. Not all patients have the same symptoms.  

Common and serious symptoms include:

Other common symptoms include: 

• Feeding difficulties in infancy 
• Vomiting and gagging 
• Abdominal pain 
• Constipation 
• Diarrhea 
• Poor weight gain and short stature 
• Farsightedness  
• Weakness 
• Easy fatigability 
• Dental problems including missing teeth and poor enamel 
• Sleep problems  
• Bed-wetting and frequent urination 

CAUSES

Most cases of Williams syndrome occur spontaneously due to a genetic change.  

Specifically, it can be caused by a deleted portion of chromosome 7. As a result, genetic material is missing from the long arm of the chromosome. This region is known as 7q11.23. 

Chromosomes carry our genes. We have 46 chromosomes in total. They are arranged in 23 pairs. We inherit one copy in each pair from our parents. Studies have shown that about 28 genes present in chromosome 7 play a role in Williams syndrome.  

Williams syndrome is an autosomal dominant disorder. This means only a single copy of an abnormal gene can cause the disease. This gene can come from either parent. The risk of passing the abnormal gene to children is 50% during each pregnancy.

LABORATORY INVESTIGATIONS

Williams syndrome is often diagnosed during early childhood with:  

• A complete medical history  
• A physical exam  

If this condition is suspected, your doctor will perform genetic testing. They will look for chromosome 7q11.23 gene deletion. 

A doctor will usually perform additional tests to look for complications. These include:

TREATMENT AND THERAPIES

Williams syndrome is a disease that affects multiple body systems. There is no cure.  

Management is aimed at relieving symptoms. Care from a variety of doctors is often recommended. Based on the symptoms, your doctor will coordinate with the appropriate specialists.  

Patients with cardiac complications often need surgery. They will require close follow-up with a cardiologist to look for further complications.  

An endocrine doctor will often manage complications including:  

• High calcium levels 
• Low levels of thyroid hormones 
• High glucose levels 
• Poor growth  

Developmental therapy can help support your child as they grow. Common therapies include:  

• Physical therapy 
• Occupational therapy  
• Speech therapy 

Patients may need medication and specific therapies for behavioral problems including:  

• ADHD  
• Anxiety 
• Phobias 

Other ways of managing Williams syndrome include:  

• Back bracing and/or surgeries. This may be needed to treat scoliosis.  
• An individualized education plan, special education supports 
• Psychosocial support for families 

OUTLOOK

Williams syndrome patients usually have a normal life expectancy. Few patients with cardiovascular complications may have reduced life expectancy. 

RELATED DISORDERS

Some disorders with similar symptoms include: 

• Noonan syndrome 
• DiGeorge syndrome 
• Fetal alcohol syndrome 
• Kabuki syndrome 

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Research 

ClinicalTrials.gov for Williams Syndrome (birth to 17 years).

These are clinical trials that are recruiting or will be recruiting. Updates are made daily, so you are encouraged to check back frequently. 

ClinicalTrials.gov is a database of privately and publicly funded clinical studies conducted around the world. This is a resource provided by the U.S. National Library of Medicine (NLM), which is an institute within the National Institutes of Health (NIH). Listing a study does not mean it has been evaluated by the U.S. Federal Government. Please read the NLM disclaimer for details.    

Before participating in a study, you are encouraged to talk to your health care provider and learn about the risks and potential benefits. 

The information in the CNF Child Neurology Disorder Directory is not intended to provide diagnosis, treatment, or medical advice and should not be considered a substitute for advice from a healthcare professional. Content provided is for informational purposes only.  CNF is not responsible for actions taken based on the information included on this webpage. Please consult with a physician or other healthcare professional regarding any medical or health related diagnosis or treatment options. 

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Twite MD, Stenquist S, Ing RJ. Williams syndrome. Paediatr Anaesth. 2019 May;29(5):483-490. https://doi.org/10.1111/pan.13620. Epub 2019 May 2. PMID: 30811742.  

Morris CA. Williams Syndrome. 1999 Apr 9 [updated 2017 Mar 23]. In: Adam MP, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews® [Internet]. Seattle (WA): University of Washington, Seattle; 1993–2022. PMID: 20301427. Available from: https://www.ncbi.nlm.nih.gov/books/NBK1249/