Clinical characteristics and immunological status of patients with 22q11.2 deletion syndrome in Northern Thailand.

ABSTRACT

BACKGROUND: 22q11.2 deletion syndrome is one of the most prevalent microdeletion syndromes in humans. The syndrome is characterized by extensive phenotypic variability. OBJECTIVE: to investigate the clinical characteristics, immunological features, and intellectual status of 22q11.2 deletion syndrome patients at Chiang Mai University Hospital, Thailand. METHODS: Patients who had a confirmed diagnosis of 22q11.2 deletion syndrome by fluorescent in situ hybridization (FISH) were enrolled. Data collated and evaluated included that pertaining to history, physical examination, laboratory testing including T-cell, immunoglobulin, calcium, thyroid and parathyroid levels in the blood, cardiac and urological imaging, and intellectual status. RESULTS: 34 patients diagnosed with 22q11.2 deletion syndrome; 18 (53%) were female. The median age of patients was 18.5 months (IQR; 1.5-35.8). Ninety-one percent of patients had characteristic facial features; 94% had a congenital heart defect with tetralogy of Fallot being the most frequent (72%); 88% had hypocalcemia, and 35% had genitourinary tract abnormalities. Recurrence of 22q11.2 deletion syndrome in the family was detected in 18% of cases. Twenty-eight patients (82%) were found to have a low number or percentage of T-cells. Five patients (15%) had low immunoglobulin levels. Intellectual disability (IQ/DQ scores < 70) were found in 20 out of 25 patients who were evaluated (80%), whereas the other five (20%) performed at a level of borderline intellectual function. CONCLUSIONS: Tetralogy of Fallot, hypocalcemia, immunologic defect, and cognitive impairment were common in our 22q11.2 deletion syndrome study group. We recommend that all affected patients have a multi-system evaluation by a comprehensive care team.