Short answer · Medically reviewed summary · Last updated: 2026-05-08
Coffin-Siris syndrome is an ultra-rare genetic disorder with an estimated birth prevalence of less than 1 in 100,000, though exact global figures remain unknown due to significant underdiagnosis. While the condition is lifelong, most cases are identified in early childhood during pediatric evaluations for developmental delays or characteristic physical features. Is Coffin-Siris syndrome common or rare? Coffin-Siris syndrome is classified as an ultra-rare condition.
What is the prevalence of Coffin Siris Syndrome?
Prevalence of Coffin Siris Syndrome: how many people are affected worldwide, differences by sex and region, with sources.
Coffin-Siris syndrome is an ultra-rare genetic disorder with an estimated birth prevalence of less than 1 in 100,000, though exact global figures remain unknown due to significant underdiagnosis. While the condition is lifelong, most cases are identified in early childhood during pediatric evaluations for developmental delays or characteristic physical features.
Is Coffin-Siris syndrome common or rare?
Coffin-Siris syndrome is classified as an ultra-rare condition. Because its clinical presentation—such as hypoplasia of the fifth digit/nail and developmental delay—can overlap with other genetic syndromes, many individuals likely remain undiagnosed or misdiagnosed. Currently, 212 people with Coffin-Siris syndrome have joined the DiseaseMaps.org community, providing a vital real-world perspective that complements clinical research data.
How does Coffin-Siris syndrome affect different populations?
Data regarding the epidemiology of Coffin-Siris syndrome indicates the following key points:
- Gender Distribution: There is no clear evidence of a sex-based bias; Coffin-Siris syndrome appears to affect males and females with equal frequency.
- Geographic/Ethnic Variation: No specific geographic or ethnic clusters have been identified, suggesting the condition occurs globally across all populations.
- Age of Onset: As a congenital genetic disorder, Coffin-Siris syndrome is present from birth, with diagnosis typically occurring in infancy or early childhood.
What are the challenges in tracking prevalence?
The primary challenge in determining the exact prevalence of Coffin-Siris syndrome is its high degree of clinical and genetic heterogeneity. Mutations in various genes (such as ARID1A, ARID1B, and SMARCA4) can cause the syndrome, leading to a wide spectrum of severity. Consequently, mild cases of Coffin-Siris syndrome may never come to medical attention, leading to an underestimation of its true prevalence in the general population.
Next steps
- Consult a clinical geneticist to discuss genetic testing options if you suspect an undiagnosed case.
- Connect with the 212 members on DiseaseMaps.org to share experiences and find peer support.
- Register with the Coffin-Siris Syndrome Foundation to stay informed about the latest research and clinical trial opportunities.
Medical disclaimer: This information is for educational purposes only and should not replace professional medical advice, diagnosis, or treatment.
References
- Orphanet: Coffin-Siris syndrome (ORPHA:198)
- NIH Genetic and Rare Diseases (GARD) Information Center
- OMIM: Coffin-Siris Syndrome 1 (Entry #135900)
- Coffin-Siris Syndrome Foundation (coffinsiris.org)
