Short answer · Medically reviewed summary · Last updated: 2026-05-08
Koolen-de Vries syndrome (KdVS), also known as 17q21.31 microdeletion syndrome, is primarily diagnosed through chromosomal microarray (CMA) testing, which detects the characteristic deletion of the 17q21.31 region. Because the clinical presentation of Koolen-de Vries syndrome is highly variable, genetic testing is essential for a definitive diagnosis, as physical symptoms alone are often insufficient to distinguish it from other neurodevelopmental disorders. How is Koolen-de Vries syndrome diagnosed? The diagnostic process for Koolen-de Vries syndrome typically begins when a pediatrician or neurologist notices a combination of developmental delays, intellectual disability, and distinctive facial features.
How is Koolen De Vries Syndrome / 17q21.31 Microdeletion Syndrome diagnosed?
How Koolen De Vries Syndrome / 17q21.31 Microdeletion Syndrome is diagnosed: tests, specialists and the diagnostic journey, told by patients and reviewed against medical sources.
Koolen-de Vries syndrome (KdVS), also known as 17q21.31 microdeletion syndrome, is primarily diagnosed through chromosomal microarray (CMA) testing, which detects the characteristic deletion of the 17q21.31 region. Because the clinical presentation of Koolen-de Vries syndrome is highly variable, genetic testing is essential for a definitive diagnosis, as physical symptoms alone are often insufficient to distinguish it from other neurodevelopmental disorders.
How is Koolen-de Vries syndrome diagnosed?
The diagnostic process for Koolen-de Vries syndrome typically begins when a pediatrician or neurologist notices a combination of developmental delays, intellectual disability, and distinctive facial features. Because these signs are broad, families often experience a "diagnostic odyssey," waiting months or years for a definitive answer. Diagnosis is confirmed via a chromosomal microarray (CMA), which identifies the deletion of the KANSL1 gene. In some cases, if CMA results are inconclusive but clinical suspicion remains high, whole-exome or whole-genome sequencing may be utilized.
What tests and examinations are involved?
Clinicians use a multidisciplinary approach to evaluate individuals suspected of having Koolen-de Vries syndrome. Standard assessments include:
- Chromosomal Microarray (CMA): The gold-standard test to identify the 17q21.31 microdeletion.
- Cardiac Evaluation: Echocardiograms are recommended to screen for common structural heart defects.
- Renal Ultrasound: Used to check for structural abnormalities of the kidneys.
- Developmental and Neuropsychological Testing: To map the extent of cognitive and speech delays.
Which specialists should be involved?
If you suspect a diagnosis of Koolen-de Vries syndrome, it is vital to consult a clinical geneticist who can interpret complex genomic data. Other specialists, such as pediatric neurologists, cardiologists, and speech-language pathologists, play critical roles in managing the specific manifestations of Koolen-de Vries syndrome. Seeking out specialists at major academic medical centers is often the most effective way to bypass the frustration of being misdiagnosed with more common conditions like autism spectrum disorder or general developmental delay.
Next steps
- Consult a board-certified clinical geneticist to order appropriate microarray testing.
- Connect with the Koolen-de Vries syndrome community at DiseaseMaps.org to share experiences with the 8 members already navigating this journey.
- Contact the Koolen-de Vries Syndrome Foundation for specialized resources and provider directories.
Medical disclaimer: This information is for educational purposes only and does not replace professional medical advice, diagnosis, or treatment from a qualified healthcare provider.
References
- NIH Genetic and Rare Diseases Information Center (GARD): Koolen-de Vries syndrome
- Orphanet: 17q21.31 microdeletion syndrome
- OMIM (Online Mendelian Inheritance in Man): #610443
- Koolen-de Vries Syndrome Foundation: kdvsfoundation.org
