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

Objective: 22q11.2 deletion syndrome (22q11.2 DS) is the most common chromosomal microdeletion disorder. Associated problems in 22q11.2 DS may include cardiac abnormalities, immune dysfunction, facial dysmorphism, with endocrine, genitourinary and gastrointestinal problems, and developmental delay. The aim of this study was to evaluate and present all endocrinological findings of patients with 22q11.2 DS from a single center. Methods: All participants had confirmed 22q11.2 DS by fluorescence in situ hybridization with hypoparathyroidism. Data were retrieved by retrospective review of patient records. Results: A total of 17 patients were reviewed. On physical examination, all patients had similar dysmorphic features. The median age at diagnosis was 45 days (1 day-13 years). 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 parathyroid hormone (PTH) was 11.5 (3.7-47.6) ng/L. Transient hypoparathyroidism was detected in five cases (29.4%). There was no significant difference between patients with permanent or transient hypoparathyroidism regarding gender, age at diagnosis, calcium, phosphorus, and PTH levels. However, vitamin D levels were significantly lower in the transient group (p=0.036). During follow-up, short stature, obesity, and type 2 diabetes mellitus were absent. Thyroid autoantibodies were detected in two patients with normal thyroid function tests. Despite there being no pathological short stature, final stature was shorter than the general population (mean height standard deviation score: -0.94±0.83). Conclusion: Hypocalcemia may be detected during acute illness in some cases where hypocalcemia appears at later ages. There was no significant difference between permanent and transient hypoparathyroidism cases in terms of PTH level. Recognition of the more specific facial findings is important to trigger investigation of genetic variants, additional anomalies, and for follow-up.

A typical 22q11.2 deletion syndrome and pseudohypoparathyroidism: A CARE compliant case report.

RATIONALE: It is rare to find 22q11.2 deletion syndrome with pseudohypoparathyroidism in children. Furthermore, the phenotypic spectrum of this disorder varies widely. PATIENT CONCERNS: A patient was diagnosed with pseudohypoparathyroidism at age 14 years because of convulsions, hypocalcemia, hyperphosphatemia, normal parathyroid hormone levels, and basal ganglia calcifications. Thereafter, the child presented with symptoms of nephrotic syndrome; subsequently, he was diagnosed with nephrotic syndrome at the local hospital. DIAGNOSIS: At our hospital, multiplex ligation-dependent probe amplification confirmed that the patient had 22q11.2 deletion syndrome. INTERVENTIONS: The patient continued to be treated with calcium supplements. OUTCOMES: Seizure activity and proteinuria ceased. LESSONS: Signs of this syndrome include delayed speech development due to velofacial dysfunction, recurrent croup attacks during early childhood due to latent hypocalcemia, and mild dysmorphic features. The findings of this patient indicated that 22q11.2 deletion syndrome may include a wide spectrum of clinical findings and that this diagnosis needs to be considered for all patients presenting with hypocalcemia, regardless of age.

Perioperative management of patients with DiGeorge syndrome undergoing cardiac surgery.

OBJECTIVE: DiGeorge syndrome is a genetic disorder with multisystem involvement resulting in craniofacial and cardiac anomalies and parathyroid and immune system dysfunction. This study describes perioperative management of a large cohort of patients with DiGeorge syndrome undergoing cardiac surgery. DESIGN: Retrospective cohort study. SETTING: Major academic tertiary institution. PARTICIPANTS: The medical records of patients diagnosed with DiGeorge syndrome and undergoing cardiac surgery at this institution, from January 1, 1976, to July 31, 2012, were reviewed for phenotypic characteristics and intraoperative and postoperative complications, with specific attention to hemodynamic instability, perioperative perturbations of plasma calcium homeostasis, and airway difficulty. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Sixty-two patients underwent 136 cardiac surgical procedures; 47 patients (76%) had multiple operations. Sternotomies for reoperations often were complex (8 complicated by vascular injury or difficulty achieving hemostasis and 5 requiring bypass before sternotomy). Two patients had persistent hypocalcemia intraoperatively, requiring infusion of calcium chloride, and hypocalcemia developed postoperatively in 8 patients. Prolonged mechanical ventilation (>24 hours) was required after 48 procedures (35%), and 25 (18%) required prolonged inotropic support (>72 hours). Infectious complications occurred after 31 procedures (23%). There was no in-hospital or 30-day mortality. CONCLUSIONS: Patients with DiGeorge syndrome often have complex cardiac anomalies that require surgical repair. The postoperative course is notable for the frequent need for prolonged respiratory and hemodynamic support. Patients can develop hypocalcemia and may require calcium supplementation. Immunodeficiencies may be associated with the increased rate of postoperative infections and may dictate the need for specific transfusion management practices.

DiGeorge syndrome/velocardiofacial syndrome: the chromosome 22q11.2 deletion syndrome.

Chromosome 22q11.2 deletion (CH22qD) syndrome is also known as DiGeorge syndrome or velocardiofacial syndrome. This deletion syndrome is extremely common with nearly one in 4000 children being affected. Recent advances and a holistic approach to patients have improved the care and well-being of these patients. This review will summarize advances in understanding the health needs and immune system of patients with CH22qD syndrome. Patients will most often need interventions directed at maximizing function for many organ systems but can ultimately have a high level of functioning.

Lower prepulse inhibition in children with the 22q11 deletion syndrome.

OBJECTIVE: The 22q11 deletion syndrome is associated with a range of possible physical anomalies, probable ongoing learning disabilities, and a specific constellation of neuropsychological deficits, including impairments in selective and executive visual attention, working memory, and sensorimotor functioning. It has been estimated that 25% of the children with 22q11 deletion syndrome go on to develop schizophrenia in late adolescence or adulthood. This is of urgent concern. Specification of early brain network vulnerabilities may provide a basis for early intervention while indicating critical links between genes and severe psychiatric illness. Neuropsychological studies of children with 22q11 deletion syndrome have implicated an array of potentially aberrant brain pathways. This study was conducted to determine whether preattentive processing ("sensorimotor gating") deficits are present in this population. METHOD: The authors administered a test of prepulse inhibition to 25 children with 22q11 deletion syndrome and their 23 sibling comparison subjects, ages 6-13. It was predicted that the children with 22q11 deletion syndrome would have lower prepulse inhibition than the comparison subjects. RESULTS: Prepulse inhibition in the children with 22q11 deletion syndrome (26.06%) was significantly less than that of the sibling comparison subjects (46.41%). Secondary analyses suggested that this decrement did not reflect developmental delay, and lower prepulse inhibition was associated with particular subsyndromal symptoms in some children. CONCLUSIONS: Sensorimotor gating is lower in children with 22q11 deletion syndrome. These findings may indicate specific brain circuits that are anomalous in 22q11 deletion syndrome.