Background: 22q11.2 deletion syndrome is a common microdeletion syndrome that affected various systems.
Objective: To determine clinical phenotypes and immunological features of 22q11.2 deletion syndrome in north-eastern Thai children compare to western countries.
Material and Method: The authors described the clinical and immunological features in 20 north-eastern Thai children with
22q11.2 deletion syndrome that were followed-up at Srinagarind Hospital.
Result: Clinical phenotypes were facial dysmorphism (100%), congenital heart disease (80%) and cleft palate (30%).
Prevalence of tetralogy of Fallot (TOF) in this syndrome was higher than in western. Serious infections were found including
pneumonia, septicemia and brain abscess. Only a patient had panhypogammaglobulinemia and subsequently died. Selective
IgA deficiency was not found. There was a twin patient conceived from intracytoplasmic sperm injection (ICSI).
Conclusion: TOF is more common in Asian patients than in western which different to selective IgA deficiency. The 22q11.2
deletion syndrome could be consequence from ICSI.

Keywords: 22q11.2 deletion, Cleft palate, Immunoglobulin, Intracytoplasmic sperm injection, Tetralogy of Fallot, Hypothyroidism