Hypoparathyroidism and 22q11 deletion syndrome

Abstract

Aims: To investigate a population of individuals with 22q11 deletion syndrome for hypocalcaemia. Methods: A detailed clinical history enquiring into symptoms of hypocalcaemia and blood sampling to assess for hypocalcaemia and hypoparathyroidism, of patients outside the neonatal period known to have the 22q11 microdeletion from fluorescent in situ hybridisation studies was taken. Results: Sixty one individuals were identified, of whom 23 were untraceable and one was unable to give informed consent. Biochemical investigations were performed on 27 subjects. Ten subjects had review of notes only. Four subjects had previously identified hypoparathyroidism. A new case of hypoparathyroidism was identified. Three subjects had borderline hypocalcaemia. Discussion: In this population of patients with 22q11 deletion syndrome, 13% of the total or 30% of those biochemically assessed had evidence of reduced serum calcium concentrations. It is likely that 13-30% of patients with 22q11 deletion syndrome have possible hypoparathyroidism outside the neonatal period. Reported symptoms of hypocalcaemia did not correlate with biochemical evidence of persisting hypocalcaemia. We have shown that previously undiagnosed asymptomatic hypoparathyroidism occurs in patients with 22q11 deletion syndrome and conclude that screening of this population should be considered.

The spectrum of parathyroid gland dysfunction associated with the microdeletion 22q11

“…The inability to increase PTH secretion appropriate for hypocalcemic stimulus can be demonstrated with a provocative test using disodium edetate infusion (8,19). It is suggested that families with 22q11 syndrome should be informed of the symptoms that might occur with hypocalcemia (20). Moreover, screening of abnormal parathyroid function should be considered in the regular follow-up of patients with del(22)(q11) (21).…”

An Adult Case of 22q11.2 Deletion Syndrome Diagnosed in a 36-year-old Woman with Hypocalcemia Caused by Hypoparathyroidism and Hashimoto's Thyroiditis

“…Congenital hypoparathyroidism typically manifests with hypocalcemia (1), with 22q11.2 deletion syndrome being recognized as its major cause (2). This syndrome, which includes DiGeorge syndrome and velocardiofacial syndrome, is caused by microdeletion of chromosome region 22q 11.2 (3).…”

“…This syndrome, which includes DiGeorge syndrome and velocardiofacial syndrome, is caused by microdeletion of chromosome region 22q 11.2 (3). It is associated with a typical facial appearance and clinical symptoms and findings such as congenital heart defects, immune deficiency caused by thymic hypoplasia, palatal cleft and mental retardation (2,4,5). In addition, autoimmunity is more common in affected patients than in the general population (6).…”

22q11.2 Deletion Syndrome: Symptoms, Diagnosis, Treatment

“…Гипопаратиреоз с/без симптоматической гипо-кальциемии (50-65% пациентов с 22q11.2DS), заболе-вания щитовидной железы с гипо-или гиперфункцией, дефицит гормона роста, внутриутробная задержка роста (около 4% пациентов), невысокий рост -основные проявления при del 22q11.2 [37][38][39]. Гипопаратиреоз с гипокальциемией обнаруживается у 50-65% пациен-тов с 22q11.2DS [40,41].…”