22q11.2 deletion syndrome in children with palatal anomaly: who and when to test?

Introduction: 22q11.2 deletion syndrome (22q11.2DS) is associated with palatal abnormalities. It remains controversial as to when and how children with palatal abnormalities should undergo specific diagnostic 22q11.2DS testing. There is also a lack of local data on the prevalence and clinical features associated with 22q11.2DS in children with cleft anomalies. We aimed to review the data on children diagnosed with 22q11.2DS who attended the cleft clinic at the Hong Kong Children's hospital.

Methods: We retrospectively reviewed the medical records of children who attended the cleft clinic at the Hong Kong Children's Hospital from January 2020 to April 2024 and had been tested for or diagnosed with 22q11.2DS. The age at genetic diagnosis, clinical features and details of palatal operation were reviewed.

Results: Based on clinical suspicions, 31 children were tested for 22q11.2DS, and of these, eight (26%) children were confirmed to have the 22q11.2DS. The majority (75%) of those tested and diagnosed received their genetic diagnosis after their palatal operations. Additionally, ten other children with 22q11.2DS were identified from hospital records, having received their genetic diagnosis elsewhere.

Conclusion: A notable number of children who attended the cleft clinic suffered from 22q11.2DS. Clinicians managing children with cleft anomalies should maintain a high index of suspicion and consider early specific 22q11.2DS genetic investigations in accordance with locally available resource and disease prevalence.