What's Williams syndrome?
Williams syndrome (Williams-Beuren syndrome) is a contiguous-gene microdeletion disorder caused by a recurrent ~1.5-1.8 Mb deletion at chromosome 7q11.23 spanning roughly 26-28 genes, almost always arising de novo. Haploinsufficiency of ELN (elastin), one of the deleted genes, drives supravalvular aortic stenosis and other vascular and connective-tissue features. Characteristic findings include SVAS and other arterial stenoses, a distinctive elfin facial appearance, mild-to-moderate intellectual disability with relative verbal strength and weak visuospatial cognition, a hallmark hypersocial personality, infantile hypercalcemia, and connective-tissue laxity. There is no disease-modifying therapy; management is surveillance and treatment of complications, including cardiovascular monitoring, calcium management, and developmental support.
| Also indexed as | ORPHA:904, MONDO:0008678 |
|---|---|
| Features mapped | 19 |
| Treatments mapped | 3 |
| Published sources | 23 |
| Last reviewed | 2026-08-04 |
Signs and symptoms
Anxiety
Anxiety is very common in Williams syndrome and often takes the form of specific fears and worries. Despite being socially outgoing, many people with the condition experience significant anxiety, which is worth addressing because it is treatable.
Short attention span
Difficulty sustaining attention is a core part of the Williams syndrome learning profile. Even alongside the famously strong verbal and social skills, attention and visual-spatial tasks are typically hard, which shapes the support a child needs at school.
Impaired visuospatial constructive cognition
A specific cognitive pattern is marked difficulty with visual-spatial tasks, such as assembling shapes or drawing, which stands out against relatively preserved language.
Intellectual disability
Most people have mild-to-moderate intellectual disability, often with particular difficulty in visual-spatial tasks but relatively strong spoken language and a sociable manner.
Peripheral pulmonary artery stenosis
In williams syndrome the elastin arteriopathy can narrow not only the aorta but other arteries, including branches of the pulmonary arteries.
Coronary artery stenosis
Coronary artery stenosis, a narrowing of the heart's blood vessels that can occur in people with Williams syndrome, can reduce blood flow to the heart muscle.
Hypertension
Williams syndrome can involve cardiovascular problems, including systemic hypertension (high blood pressure).
Supravalvular aortic stenosis
Supravalvular aortic stenosis is a narrowing of the aorta just above the heart valve. It is the most characteristic heart problem in the condition and comes from the loss of elastin, so the heart and arteries are monitored over time.
Autosomal dominant inheritance
A few cases of Waardenburg syndrome run in families and are passed down when just one parent carries the gene change, while most cases happen by chance.
Hypercalcemia
High blood calcium (hypercalcemia) is common in infancy and can cause irritability, poor feeding, and vomiting. It usually settles but sometimes needs treatment, so calcium is checked early.
Vesicoureteral reflux
Vesicoureteral reflux is a common condition in children where a problem with how the ureter connects to the bladder allows urine to flow backward.
Hypodontia
People with PITX2-related ARS have umbilical anomalies and missing or small teeth, and they often develop an extra pouch in the small intestine.
Microdontia
Patients with PITX2-related ARS can have abnormally small teeth and/r missing teeth.
Retinal arteriolar tortuosity
Fundus examination reveals twisted blood vessels in the back of the eye, along with vision loss and thinning of certain retinal layers.
Feeding difficulties in infancy
Babies with Williams syndrome often have trouble feeding in the early months, which can contribute to slow weight gain. Feeding problems are frequently one of the first concerns parents notice before the diagnosis is made.
Constipation
Constipation is among the clinical symptoms observed.
Overfriendliness
People with williams syndrome often have a strikingly outgoing, overfriendly personality, with an unusual eagerness to interact socially with strangers.
Abnormal social behavior
A hallmark is a distinctive hypersocial personality: people are typically very friendly, empathetic, and drawn to others, sometimes with little wariness of strangers and higher rates of anxiety.
Elfin facies
The face has a characteristic appearance sometimes called elfin: a broad forehead, full cheeks, a short upturned nose, wide mouth, and full lips. These features help clinicians recognise the condition.
How it is diagnosed
Williams syndrome
Diagnosed using: fluorescent in situ hybridization for 7q11.23 microdeletion.
“This study aimed to detect the 7q11.23 microdeletion in 10 patients with early clinical diagnosis of WBS using fluorescent in situ hybridization or array comparative genomic hybridization. As an alternative method, multiplex ligation-dependent probe amplification (MLPA) was used to confirm this microdeletion.”
Williams syndrome
Diagnosed using: echocardiography.
“Prenatal echocardiogram showed supravalvular aortic stenosis and pulmonary stenosis.”
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.
surgical repair of supravalvar aortic stenosis
Some people with Williams syndrome have supravalvar aortic stenosis, a narrowing of the aorta, severe enough to need surgical repair. Care is otherwise directed at the specific features each person has.
Used to help with: Williams syndrome.
“Its severity varies: ~20% of people with Williams-Beuren syndrome have SVAS requiring surgical intervention, whereas ~35% have no appreciable SVAS.”
surgical correction of supravalvular aortic stenosis
The main treatment for the supravalvular aortic stenosis of williams syndrome is surgical correction of the narrowed arteries.
Used to help with: Williams syndrome.
“Definitive therapy for supravalvar aortic stenosis consists of surgical correction of the arteriopathies.”
pamidronate for severe hypercalcemia
For the rare severe high-calcium episodes of williams syndrome, intravenous pamidronate has been used in a few reported cases.
Used to help with: Williams syndrome.
“The need for pamidronate therapy has been reported in a few cases of Williams syndrome with severe hypercalcemia.”
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.
variable expressivity
Although the deletion is highly penetrant, how the syndrome shows up varies widely from person to person, so the range and severity of features differ even with the same deletion.
Described as modulating: Williams syndrome.
“Williams-Beuren syndrome (WBS) is a chromosomal microdeletion syndrome with variable phenotypic features such as supravalvular aortic stenosis (SVAS), facial appearance characteristics, growth retardation, and infantile hypercalcemia.”
GTF2I and GTF2IRD1
The cognitive and behavioral traits of williams syndrome are thought to involve loss of the GTF2I family genes (GTF2I and GTF2IRD1), though no single gene has been firmly confirmed as responsible.
Described as modulating: Williams syndrome.
“There are still no genes in the region that have been consistently linked to the cognitive and behavioral phenotypes, although human studies and mouse models have led to the current hypothesis that the general transcription factor 2 I family of genes, GTF2I and GTF2IRD1, are responsible.”
ELN haploinsufficiency
The narrowing of the aorta seen in williams syndrome comes from loss of one working copy of the elastin gene (ELN); supravalvular aortic stenosis is a systemic elastin arteriopathy.
Described as modulating: Williams syndrome.
“Supravalvular aortic stenosis is a systemic elastin (ELN) arteriopathy that disproportionately affects the supravalvular aorta.”
LIMK1
Williams syndrome has two cognitive hallmarks: marked visuospatial difficulty alongside relatively stronger verbal ability, and a hypersocial personality.
Described as modulating: Williams syndrome.
“…two cognitive/behavioural hallmarks: marked visuospatial deficits relative to verbal and non-verbal reasoning abilities and hypersocial…”
How to read the evidence labels
Where this comes from
This guide is built from 23 published source(s). Every claim above links back to one of them. Click any source ID to read the original on PubMed.
Take it further
Printed, source-linked documents built from this condition's graph — ready to bring to an appointment or attach to a coverage request. Every claim carries its published source, the same as this guide.