witteveen–kolk syndrome witteveen–kolk syndrome witteveen–kolk syndrome, also known as witkos and 15q24 microdeletion syndrome, is a rare neurodevelopmental disorder characterized by developmental delay/intellectual disability, facial dysmorphisms, and short stature. the syndrome is caused by loss of function of switch‐insensitive 3 transcription regulator family member a (sin3a). the syndrome was discovered by developmental neuroscientists josefine s. witteveen, phd and sharon m. kolk, phd, in 2016.