Emmy Verheij
Although it is a relatively unknown syndrome, 22q11.2 deletion syndrome occurs rather frequently. The prevalence is estimated at 1: 2,000 – 4,000 live births. The great variability in phenotype makes it a very scientifically interesting syndrome because many different organs can be impacted. Balance disorder is one of the described features in this syndrome and it was thought that this is mainly a result of hypotonia and motor development delay. Recently, however, there is growing evidence that suggests the inner ears of some of these patients suffer from anatomical malformations. This was confirmed in our paper.
In my opinion, the collaboration between the University Medical Center Utrecht and the Children’s Hospital of Philadelphia added great value to our study. We collected all the available CT and MR images of the mastoid bones of children with 22q11.2 deletion syndrome who were in care in 1 of the 2 centers. Our paper showed a high number of children (62% of ears) with a malformation of the lateral semicircular canal. We hypothesized that vestibular problems due to a malformed vestibular system might play a role in balance problems.
We are also currently conducting a study investigating the vestibular system in patients with 22q11.2 deletion syndrome. We are studying the function of the vestibular system using electronystagmography and ocular vestibular-evoked myogenic potentials. With MR imaging, we will determine whether there are anatomic malformations and will obtain information on motor development from youth health care centers. With this study, we hope to gain more insight to balance problems of these patients and aim to clarify the etiology in order to help improve symptomatic care. Additionally, more subtle balance problems, such as difficulty walking in the dark, may be better recognized.