Because of errors in embryogenesis of the third and fourth pharyngeal arches, parathyroid hypoplasia or aplasia is common and results in hypocalcemia. The prevalence of hypocalcemia in this patient population ranges from 32% to 80%. Hypocalcemia can be transient in neonates or can be permanent, requiring calcium and vitamin D supplementation. Because hypocalcemia can be difficult to detect in the neonate, a high index of suspicion is necessary if a neonate exhibits irritability, jitteriness, twitching, seizure activity, failure to thrive, tachycardia, and hypotension. Stridor (which needs to be differentiated from laryngeal web, which is also prevalent in 22q11 deletion syndrome) and carpopedal spasm can also occur. It is important to remember that in patients with this syndrome, hypocalcemia can be precipitated by the stress of surgery and by increased needs during puberty or pregnancy. Chronic hypocalcemia can result in poor dentition that is prone to caries.

The prevalence of thyroid disease is significantly higher in the pediatric population with 22q11 deletion syndrome than in the general pediatric population. Some sources suggest that screening for thyroid disease, including blood tests for thyroid function and immunity, as well as a thyroid ultrasound, should be added to the routine medical management of these children.

References

• Lin HY, Tsai WY, Tung YC, et al. Endocrine and growth disorders in Taiwanese children with 22q11.2 deletion syndrome. Front Endocrinol (Lausanne). 2022;13:771100.
• Ricci S, Sarli WM, Lodi L, et al. Characterization of autoimmune thyroid disease in a cohort of 73 paediatric patients affected by 22q11.2 deletion syndrome: longitudinal single-centre study. Genes (Basel). 2022;13:1552.
• Root AW. Disorders of Mineral Metabolism: Normal homeostasis. In: Sperling MA, ed. Pediatric Endocrinology. 5th ed. Elsevier Health Sciences; 2021:220-278.