What is the history of Koolen De Vries Syndrome / 17q21.31 Microdeletion Syndrome?

Koolen-de Vries syndrome, also known as 17q21.31 microdeletion syndrome, was first identified in 2006 by Dr. David Koolen and Dr. Bert de Vries. This rare genetic condition, caused by the deletion or mutation of the KANSL1 gene, was historically difficult to diagnose until the advent of high-resolution chromosomal microarray technology.

How was Koolen-de Vries syndrome first discovered?

Before 2006, children with the characteristic features of Koolen-de Vries syndrome were often undiagnosed or misdiagnosed due to the limitations of standard karyotyping. In 2006, a research team led by Dr. David Koolen and Dr. Bert de Vries utilized advanced microarray analysis to identify a recurrent microdeletion on chromosome 17q21.31. This breakthrough allowed clinicians to finally group patients with similar developmental delays, unique facial features, and hypotonia under a single, definitive clinical diagnosis.

How has our understanding of 17q21.31 microdeletion syndrome evolved?

Initially, Koolen-de Vries syndrome was defined solely by the deletion of the 17q21.31 region. However, as genetic sequencing technology improved, researchers discovered that mutations specifically within the KANSL1 gene could cause the same phenotype even without the full deletion. This expanded the clinical definition of Koolen-de Vries syndrome and allowed for more precise genetic testing.

What are the major milestones in the history of this condition?

• 2006: First clinical description of Koolen-de Vries syndrome by Koolen and de Vries.


• 2012: Identification of KANSL1 haploinsufficiency as the primary cause of the syndrome's features.


• Present: Growing recognition of the multisystemic nature of the condition, including epilepsy, cardiac, and renal involvement.

How has patient advocacy changed the landscape?

The history of Koolen-de Vries syndrome is deeply intertwined with the rise of patient-led advocacy. As families connected globally, they pushed for better clinical guidelines and research. Today, 8 people with Koolen-de Vries syndrome have joined the DiseaseMaps.org community, demonstrating how digital platforms help bridge the gap between rare disease research and the lived experience of patients and their families.

Next steps

• Consult a clinical geneticist to review the latest molecular testing options for Koolen-de Vries syndrome.


• Connect with the Koolen-de Vries Syndrome Foundation for educational resources and family support.


• Join the community at DiseaseMaps.org to share experiences and learn from others navigating this diagnosis.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment.

References

• Orphanet: Koolen-de Vries syndrome (ORPHA:168535)


• NIH GARD: 17q21.31 microdeletion syndrome


• OMIM: 17q21.31 deletion syndrome (#610443)


• Koolen-de Vries Syndrome Foundation (kdvs.org)