title: Parathyroid gland dysfunction in 22q11.2 deletion syndrome.
abstract: BACKGROUND
  22q11 deletion syndrome (22q11DS) is characterized by conotruncal cardiac defects and hypoplasia of parathyroid glands and thymus, which result in variable hypoparathyroidism (HPT) and immune deficiency.
  
  
  METHODS
  To study the course of HPT and the spectrum of other associated manifestations we evaluated all patients with 22q11DS, confirmed by fluorescence in situ hybridization, and HPT who were under follow-up at the Calcium-bone clinic, The Hospital for Sick Children, Toronto. Patients were clinically assessed and their hospital records were reviewed.
  
  
  RESULTS
  Eighteen patients were included. At follow-up assessment at median age of 7.3 years HPT was judged complete in 11 (61%) and partial in 7 patients (39%). Patients with complete HPT presented with hypocalcemia later (median age at diagnosis 2.4 vs. 0.0 years) and more often with a hypocalcemic seizure than patients with partial HPT (73 vs. 29%). The spectrum of other associated manifestations did not differ between the groups.
  
  
  CONCLUSIONS
  HPT in patients with 22q11DS is often partial. Many of the patients present with a hypocalcemic seizure which is predictive of complete HPT. Patients with complete and partial HPT do not differ in respect to their other associated features. Patients with features of 22q11DS should be actively screened for hypocalcemia to prevent development of symptomatic hypocalcemia.
authors.affiliation: Division of Endocrinology, The Hospital for Sick Children, University of Toronto, Toronto, Canada.
authors.forename: Fayza
authors.initials: F
authors.lastname: Al-Jenaidi
authors.forename: Outi
authors.initials: O
authors.lastname: Makitie
authors.forename: Eyal
authors.initials: E
authors.lastname: Grunebaum
authors.forename: Etienne
authors.initials: E
authors.lastname: Sochett
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002872:Chromosome Deletion; D002892:Chromosomes, Human, Pair 22; D005260:Female; D006801:Humans; D007011:Hypoparathyroidism / Q000235:genetics* / Q000503:physiopathology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010280:Parathyroid Glands / Q000503:physiopathology*; D012189:Retrospective Studies; D013577:Syndrome