Short answer · Medically reviewed summary · Last updated: 2026-05-08

Weaver Syndrome is a rare genetic overgrowth disorder characterized by accelerated bone maturation, tall stature, and distinct facial features. It is primarily caused by pathogenic variants in the EZH2 gene, leading to systemic physical and developmental differences that typically manifest in early childhood. What are the primary characteristics of Weaver Syndrome? Individuals with Weaver Syndrome often present with a recognizable pattern of physical traits.

What is Weaver Syndrome

Name: What is Weaver Syndrome
Creator: DiseaseMaps Editorial Team
Published: 2016-10-31UTC22:48:33.0000000

What is Weaver Syndrome? Plain-language, medically reviewed definition plus the lived reality told by patients.

Weaver Syndrome is a rare genetic overgrowth disorder characterized by accelerated bone maturation, tall stature, and distinct facial features. It is primarily caused by pathogenic variants in the EZH2 gene, leading to systemic physical and developmental differences that typically manifest in early childhood.

What are the primary characteristics of Weaver Syndrome?

Individuals with Weaver Syndrome often present with a recognizable pattern of physical traits. While symptoms vary, the most common clinical features include:

Advanced bone age (skeletal maturation occurring faster than chronological age).

Macrosomia (large birth weight) and rapid postnatal growth.

Distinctive craniofacial features, such as a broad forehead, hypertelorism (widely spaced eyes), and a small chin (micrognathia).

Variable degrees of intellectual disability or developmental delay.

Hypertonia (increased muscle tone) and instability in gait.

What causes Weaver Syndrome?

Weaver Syndrome is caused by mutations in the EZH2 gene, which provides instructions for making a protein involved in regulating gene expression. This condition is typically inherited in an autosomal dominant pattern, meaning a single copy of the altered gene is sufficient to cause the disorder. However, many cases of Weaver Syndrome occur as de novo (new) mutations in individuals with no family history of the condition.

How common is Weaver Syndrome?

Weaver Syndrome is an extremely rare condition. Because it is often underdiagnosed or misdiagnosed due to its overlapping features with other overgrowth syndromes, exact prevalence rates are unknown. Worldwide, only a few hundred cases have been documented in medical literature. At DiseaseMaps.org, we currently support a small but growing cohort of 6 community members who share their experiences with this rare diagnosis.

How is Weaver Syndrome differentiated from other conditions?

It is often compared to Sotos syndrome, another overgrowth disorder. However, Weaver Syndrome is clinically distinct due to its specific pattern of accelerated bone maturation and unique facial morphology. Genetic testing remains the gold standard for confirming a diagnosis of Weaver Syndrome and distinguishing it from other genetic overgrowth syndromes.

Next steps

Consult with a clinical geneticist to discuss molecular testing and family counseling.

Schedule regular evaluations with a pediatric endocrinologist to monitor growth and bone age.

Connect with the DiseaseMaps.org community to share resources with other families.

Seek early intervention services for developmental or speech delays.

Medical disclaimer: This information is for educational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of your physician regarding any medical condition.