Dissecting the Phenotypic Spectrum and Complexity of Movement Disorders in 22q11.2 Deletion Syndrome.

BACKGROUND AND PURPOSE: Movement disorders are increasingly recognized as late-occurring neurologic manifestations of 22q11.2 deletion syndrome (22q11.2DS). We aimed to dissect the spectrum of relevant movement disorders in 22q11.2DS, including clinical and electrophysiologic presentations and effective therapies.

METHODS

Retrospective review of medical records, medication histories, and videotaped examinations was conducted in 31 unrelated adults (55% female) diagnosed with 22q11.2DS and a movement disorder who were seen at a major center of excellence from June 1996 to September 2023. Between-group comparisons were performed to explore the influence of medications on movement disorder presentations.

RESULTS

The median age at movement disorder onset was 35.5 (IQR: 22.0) years. Non-parkinsonian tremor was the most common phenotype (21/31, 68%), followed by parkinsonism (13/31, 42%), dystonia (11/31, 36%), myoclonus (9/31, 29%), dyskinesia (6/31, 19%), stereotypies, and functional movement disorders (4/31, 13% each). The majority of patients (24/31, 77%) presented with two or more movement disorder phenotypes (median 3, range: 2-7). Similar trends in prevalence emerged after accounting for antipsychotic exposure and potential drug-related movement disorders. Electrophysiological assessments identified both previously described and novel motor phenotypes. Treatment data for at least one movement disorder (available for 20/31, 65%) indicated a positive response to standard phenotype-based interventions.

CONCLUSIONS

We demonstrate that movement disorders in adults with 22q11.2DS exhibit greater clinical complexity than previously reported, which could reflect innate vulnerability and pathologic mechanisms beyond medication side effects. In those with a confirmed 22q11.2 microdeletion, periodic neurologic evaluations, supported by electrophysiologic investigations, enable accurate diagnosis and implementation of personalized management strategies.