Williams Syndrome: Meaning, Causes, Symptoms, Treatment

Written by Medicover Team and Medically Reviewed by Dr Leenatha Reddy Nedurumalli , pediatrician

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Williams Syndrome is a rare genetic condition that occurs when a small piece of chromosome 7 is missing. This missing segment includes several genes, most importantly the ELN gene, which is responsible for producing elastin, a protein that helps blood vessels and tissues stay flexible. The loss of these genes affects multiple areas of growth and development.

Children and adults with Williams Syndrome usually have a unique combination of features like distinctive facial appearance, mild to moderate intellectual disability, heart and blood vessel problems and an unusually friendly and social personality. Many people with this syndrome also show particular strengths like a love for music, strong verbal skills and an empathetic nature.

Williams Syndrome is considered rare, affecting about 1 in 7,500 to 10,000 births worldwide. People with Williams Syndrome can achieve steady developmental progress and lead meaningful, fulfilling lives with early diagnosis, medical care and supportive therapies.

Types of Williams Syndrome

Williams Syndrome can present in slightly different forms depending on the size and nature of the genetic deletion on chromosome 7. Doctors generally classify it into two categories:

• Classic Williams Syndrome: This is the most common type, caused by the deletion of around 26 genes in the 7q11.23 region. Children with classic WS usually show facial features, cardiovascular problems like supravalvular aortic stenosis, developmental delays and behavioural characteristics associated with the condition.
• Atypical Williams Syndrome: In some cases, the genetic deletion may be smaller or affect a slightly different portion of chromosome 7. These people may experience mild symptoms or a different set of health, developmental or behavioural challenges. The severity and exact appearance can vary depending on which genes are missing.

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What are the Symptoms of Williams Syndrome?

Williams Syndrome shows various signs that may begin in infancy and become more noticeable as a child grows. It is important to know that every person has a different set of features and many share common characteristics that help doctors recognise the condition.

• Distinctive facial Appearance: Children have unique facial traits such as a broad forehead, short nose with a flat bridge, wide mouth, full cheeks and a small chin. These features may become more noticeable with age.
• Heart and blood vessel problems: Narrowing of blood vessels like supravalvular aortic stenosis is common. This can cause heart murmurs, high blood pressure or other cardiovascular complications.
• Developmental delays: Babies and children may sit, walk or talk later than expected. Fine motor skills like using hands for writing or dressing also develop slowly.
• Learning difficulties: Most children have mild to moderate intellectual disability but skill development is uneven. For example, they may be strong in some areas like speech but struggle with math or problem-solving.
• Behavioural traits: Children with WS are described as extremely friendly, outgoing and talkative. While this is a strength but it can sometimes lead to overtrusting behaviour.
• Speech and language development: Verbal abilities are better than expected compared to overall learning level but understanding complex ideas may remain a challenge.
• Motor and coordination issues: Poor balance, weak muscle tone and difficulty with coordination are common.
• Dental abnormalities: Small, crooked or widely spaced teeth may develop as children grow.
• Feeding problems in infancy: Babies with WS may have trouble sucking, swallowing or gaining weight.
• Hearing sensitivity (hyperacusis): Many children are susceptible to loud or sudden sounds, which can cause fear or discomfort.

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What are the Causes of Williams Syndrome?

Williams Syndrome is caused by a genetic deletion on chromosome 7q11.23, which affects about 26 genes like the ELN gene, responsible for producing elastin. Here are some common causes of Williams syndrome:

• Chromosomal deletion: The missing section of chromosome 7 causes the characteristic combination of heart problems, developmental delays and unique personality traits.
• Not usually inherited: In most cases, the deletion happens randomly during the formation of sperm or egg cells. This means parents of a child with WS typically do not carry the condition themselves.
• Rarely inherited: If one parent has Williams Syndrome, there is about a 50% chance that the condition will be passed on to their child.

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Williams Syndrome Features

Williams Syndrome is recognised by a unique combination of physical, developmental, medical and personality-related features.

• Physical features: Children with WS have distinctive facial characteristics such as a broad forehead, puffiness around the eyes, a short nose with a flat bridge, a wide mouth with a prominent chin and dental irregularities like small or widely spaced teeth. Some may also have shorter height compared to their peers.
• Cognitive features: Most people have mild to moderate learning difficulties and many show relative strengths in speech, music and memorisation.
• Personality features: One of the key aspects of WS is the highly sociable, empathetic and talkative personality. Children are described as overfriendly and may approach strangers without hesitation.
• Medical features: Cardiovascular problems like supravalvular aortic stenosis are common. Feeding difficulties in infancy, hyperacusis and musculoskeletal issues such as joint stiffness or scoliosis may also be present.

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Williams Syndrome Behaviour Problems

Although children and adults with Williams Syndrome are known for their warm, engaging and social personalities, they may also experience significant behavioural and emotional challenges that affect daily life.

• Anxiety and phobias: Many people show excessive worry. They may develop strong fears of loud noises, medical procedures or separation from parents.
• Attention deficit and hyperactivity: Difficulty sitting still, staying focused on tasks or completing activities is common and resembles ADHD-like symptoms.
• Impulsivity: Acting without thinking is a common challenge that can sometimes lead to accidents or safety risks.
• Overfriendliness: While being very social is a strength, it can also become a risk factor, as children may be overly trusting of strangers and unaware of potential dangers.
• Emotional sensitivity: Rapid mood swings, frustration or difficulty handling stressful situations are common.

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What are the Complications of Williams Syndrome?

Williams Syndrome can affect different aspects of health and development. If the condition is not recognised and properly managed, it may cause several health issues. These may vary in severity from person to person but common issues include:

• Cardiovascular complications: The most serious health concern is heart and blood vessel problems like supravalvular aortic stenosis. This can result in heart murmurs, high blood pressure or other cardiac issues that may require lifelong care or surgery.
• Growth and feeding difficulties: Many infants with WS have feeding issues, which can result in poor weight gain and slow growth in the first years of life. Some children may also remain shorter in stature compared to their peers.
• Learning and academic challenges: Although children with WS have strengths in speech and music, difficulties with problem-solving, abstract thinking and mathematics can affect academic and future employment opportunities.
• Emotional and social problems: Anxiety, depression and difficulty coping with stress are common. Overfriendliness and a trusting nature can also lead to safety concerns and social misunderstandings.
• Hearing issues: Many children are sensitive to loud sounds (hyperacusis). Over time, some may also develop partial hearing loss.
• Dental and skeletal abnormalities: Crooked teeth, small teeth or widely spaced teeth are common along with joint stiffness, scoliosis or other musculoskeletal concerns.

When to See a Doctor

Parents should consult a doctor or genetic specialist if their child shows:

• Delayed milestones in sitting, walking or speech.
• Distinctive facial features with heart murmurs.
• Overly friendly or unusual social behaviour.
• Feeding difficulties or poor growth in infancy.
• Sensitivity to sound or frequent irritability.

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Diagnosis of Williams Syndrome

Since many signs of Williams Syndrome overlap with other conditions, doctors use physical examination, medical tests and genetic studies to confirm the diagnosis.

• Clinical evaluation: Doctors begin with a detailed physical exam, checking for characteristic facial features, growth delays, speech development and behaviour patterns such as overfriendliness or anxiety.
• Cardiac assessment: Because heart and blood vessel problems are common in WS, tests such as an echocardiogram or electrocardiogram (ECG) are performed to detect narrowing of blood vessels or other cardiac concerns.
• Genetic testing:
• Fluorescence in situ hybridisation (FISH) is one of the earliest tests used to detect the deletion on chromosome 7.
• Chromosomal microarray (CMA) is now commonly used to confirm the diagnosis by identifying the missing segment of chromosome 7q11.23.
• Other evaluations: To assess the broader impact of the condition, doctors may recommend hearing tests for hyperacusis or hearing loss, dental exams, developmental and learning assessments and blood pressure monitoring to check for hypertension.

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Treatment & Management of Williams Syndrome

Williams Syndrome treatments focus on effective management of symptoms, reducing complications and improving quality of life. Because WS affects multiple systems, care usually involves a multidisciplinary team of specialists.

1. Lifestyle and Daily Care

A balanced diet and regular physical activity support healthy growth and cardiovascular health. Since many children are sensitive to loud sounds, limiting exposure to sudden or harsh noise can reduce stress and discomfort.

2. Therapies

Therapies are the basics of daily management for WS:

• Speech therapy can help in improving language skills and communication abilities.
• Occupational therapy can be helpful for fine motor skills, independence and coordination.
• Behavioural therapy is very supportive in managing impulsivity, anxiety and social challenges.
• Music therapy is very helpful in encouraging learning and emotional expression as children with WS show a strong interest in music.

3. Williams Syndrome Treatment

Continuous medical care is essential to manage health-related complications:

• Cardiac care: Regular monitoring, medications or surgery to treat heart and blood vessel problems.
• Medications: Used when necessary for anxiety, ADHD-like symptoms or severe behavioural concerns.
• Dental and vision care: Regular check-ups to address common dental abnormalities and vision issues.

4. Educational Support

Children with WS require personalised education plans that are developed based on their strengths in language and social interaction by addressing difficulties in math, problem-solving and abstract reasoning./p>

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Williams Syndrome Prognosis

The long-term outlook varies depending on the severity of cardiovascular problems, learning difficulties and behavioural challenges.

• Childhood development: Many children with WS learn to walk, talk and attend school, although they usually require extra support through special education and therapies. With early interventions, children develop strong communication and social skills, even if learning difficulties remain.
• Adulthood: Some adults with WS can work in supervised or supported environments, participate in community activities and live semi-independently. Others may need daily assistance depending on the severity of their condition.
• Life expectancy: Most people with Williams Syndrome have a normal life expectancy. However, regular monitoring of the heart and blood vessels is essential, as cardiovascular complications are associated with this condition.

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Conclusion

Williams Syndrome is a rare but manageable genetic disorder that affects growth, behaviour, learning and health. With timely diagnosis, therapies, medical care and strong family support, children and adults with Williams Syndrome can develop their abilities and enjoy a good quality of life.

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