Williams Syndrome
Autosomal Dominant Microdeletion Syndrome
Primary risk age: Apparent in infancy and early childhood (Lifelong condition)
- Urgency
- Moderate
- Typical age
- Apparent in infancy and early childhood (Lifelong condition)
- Body system
- Genetic & Chromosomal
Typical course: This is a lifelong genetic microdeletion syndrome requiring ongoing medical and developmental support.
Reviewed against AAP · CDC · WHO · NHS guidance Last reviewed 2026-06-13
1. Summary & Pathophysiology
Autosomal Dominant Microdeletion Syndrome
Pathophysiology (Development Path)
The deletion of the elastin gene causes vascular abnormalities, particularly supravalvular aortic stenosis. Deletion of other genes in the region affects neurodevelopment, leading to characteristic facial features, cognitive profile, and connective tissue laxity.
Primary Causes & Etiology
A microdeletion of approximately 26-28 genes on chromosome 7q11.23, including the elastin gene (ELN).
2. Symptom Continuum
- Early Onset Signs
Infantile hypercalcemia (high calcium levels causing irritability and feeding difficulties), low birth weight, and a distinct "elfin" facial appearance (broad forehead, short nose with a broad tip, full cheeks, and wide mouth with full lips).
- Progressive Phase
Developmental delays, mild to moderate intellectual disability, a unique "cocktail party" personality (highly social, friendly, empathetic, and loquacious), and an extreme affinity/sensitivity to music.
- Severe Indicators
Supravalvular Aortic Stenosis (SVAS - narrowing of the aorta just above the valve), renal artery stenosis causing severe hypertension, and progressive joint contractures.
3. Clinical Verification
Confirmed by Fluorescence In Situ Hybridization (FISH) or chromosomal microarray showing the deletion on chromosome 7q11.23.
4. Care & Elements Plan
Primary Care Treatment Plan
Supportive multidisciplinary care. Perform baseline and regular echocardiograms to monitor the aorta and heart. Monitor blood calcium levels in infancy. Provide early intervention speech, occupational, and physical therapies.
Home Support Elements
Support developmental and learning needs. Avoid calcium-fortified foods and excess vitamin D in infancy if hypercalcemia is present. Manage anxiety and sensory sensitivities.
Generic Active Ingredients (No Brands)
- None. Treatment is supportive
- surgical correction may be needed for severe supravalvular aortic stenosis.
Lists active elements only. Never administer self-designed therapies.
5. Doctor Critical Lines
Critical Thresholds: When to See a Doctor
Seek pediatric evaluation if an infant is unusually irritable, has feeding issues (hypercalcemia signs), or exhibits the characteristic facial features or a heart murmur.
6. Vaccine & Prevention
Routine Prophylaxis (Prevention)
No preventative measures exist, as the microdeletion is typically a random, de novo event.
Immunization Context
No specific immunizations are associated with this genetic deletion.
7. Timelines & Outlook
Active Timeline
This is a lifelong genetic microdeletion syndrome requiring ongoing medical and developmental support.
Expected Prognosis
Good. Most individuals live happy, active lives, though they require varying levels of support in adulthood. Cardiovascular complications dictate life expectancy.
Potential Untreated Complications
Supravalvular aortic stenosis, severe hypertension, chronic hypercalcemia, joint contractures, and severe anxiety.
More in Single-Gene Disorders & Multi-System Deletions
Severe Cystic Fibrosis (CF)
Autosomal Recessive Multi-System Exocrine Disorder
Infancy through Adulthood (Screened at birth; symptoms develop in infancy)
Severe Prader-Willi Syndrome (PWS)
15q11-q13 Paternal Chromosomal Deletion Syndrome
Neonates through adulthood (recognized at birth due to hypotonia)
Moderate Fragile X Syndrome (FXS)
FMR1 Gene Trinucleotide Repeat Expansion Syndrome
Toddlers through adulthood (diagnosed as speech and social delays appear)