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

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.