An Endocrinological Perspective on 22q11.2 Deletion Syndrome: A Single-center Experience.

INTRODUCTION: 22q11.2 deletion syndrome (22q11.2 DS) is the most common chromosomal microdeletion disorder. Associated problems with this syndrome may include cardiac abnormalities, immune dysfunction, facial dysmorphism, endocrine, genitourinary and gastrointestinal problems, and developmental delay. This study aims to evaluate and present all endocrinological findings of patients with 22q11.2 DS.

MATERIALS AND METHODS: The seventeen participants in this study were all FISH confirmed 22q11.2 DS cases with hypoparathyroidism who had been followed in our Pediatric Endocrinology clinic.

RESULTS: In the physical examination, it was observed that all patients had similar facial findings. The median age at diagnosis was 45 days (1 day-13 year). Most cases (64.7%, 11/17) were diagnosed with hypoparathyroidism incidentally after routine tests. At the time of diagnosis, mean calcium was 7.04±0.80 mg/dl, phosphorus was 6.2±1.1 mg/dl, and median PTH was 11.5 ng/L (3.7-47.6). Transient hypoparathyroidism was detected in five cases (29.4%). There was no significant difference between permanent and transient hypoparathyroidism cases regarding gender, age at diagnosis, calcium, phosphorus, and PTH. But vitamin D deficiency was noted in the transient cases. During follow-up short stature, obesity, and type 2 diabetes mellitus were not detected. Thyroid autoantibodies were detected in two patients with normal thyroid function tests. Pathological short stature was not seen in patients, but their final stature was shorter than the general population (mean height SDS: -0.94±0.83).

CONCLUSIONS: Hypocalcemia may detect during acute illness in some cases where hypocalcemia appears in advanced age. There was no significant difference between permanent and transient hypoparathyroidism cases in PTH levels. Recognition of the more specific facial findings mentioned in the study is important regarding genetic diagnosis, additional anomaly, and follow-up.