title: Diverse genetic aetiologies and clinical outcomes of paediatric hypoparathyroidism.
abstract: BACKGROUND
  Hypoparathyroidism is characterized by hypocalcaemia, hyperphosphataemia, and low or inappropriately normal parathyroid hormone (PTH) levels. Idiopathic or genetic drivers are the predominant causes of hypoparathyroidism in paediatric-age patients.
  
  
  OBJECTIVE
  This study investigated the aetiology and clinical course of primary hypoparathyroidism in infancy and childhood.
  
  
  METHODS
  This study included 37 patients (23 males, 14 females) with primary hypoparathyroidism diagnosed prior to 18 years of age. We analysed aetiologies, initial presentation, age at diagnosis, endocrine and radiological findings, and outcomes.
  
  
  RESULTS
  The median age at presentation was 1·7 months (range 1 day-17 years), and the mean follow-up duration was 7·0 ± 5·3 years (range 0·5-16·8 years). Our cohort included 22 cases (59·5%) of 22q11·2 microdeletion syndrome. Other aetiologies included hypoparathyroidism-deafness-renal dysplasia syndrome (5/37, 13·5%) and one patient each with autoimmune polyglandular syndrome type 1, Kearns-Sayre syndrome and Kenny-Caffey syndrome. The remaining 7 (18·9%) patients were classified as idiopathic hypoparathyroidism cases. Among the 15 patients who underwent brain imaging, 5 (33·3%) had basal ganglia calcification. Among the 26 patients examined by renal imaging, 5 (19·2%) had either nephrocalcinosis or a renal stone. After 11 months of calcium or calcitriol supplementation, 16 patients (43·2%) discontinued medication. The final PTH levels were significantly higher in patients with transient hypoparathyroidism than those with permanent hypoparathyroidism.
  
  
  CONCLUSIONS
  Identification of the genetic aetiologies of hypoparathyroidism makes it possible to predict patient outcomes and provide appropriate genetic counselling. Long-term treatment with calcium and calcitriol necessitates monitoring for renal complications.
authors.affiliation: Department of Paediatrics, Asan Medical Centre Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Ja Hye
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Paediatrics, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea.
authors.forename: Young-Lim
authors.initials: YL
authors.lastname: Shin
authors.affiliation: Department of Paediatrics, Gangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Seung
authors.initials: S
authors.lastname: Yang
authors.affiliation: Department of Paediatrics, Children's Hospital, Pusan National University, Yangsan, Korea.
authors.forename: Chong Kun
authors.initials: CK
authors.lastname: Cheon
authors.affiliation: Department of Paediatrics, Asan Medical Centre Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Ja Hyang
authors.initials: JH
authors.lastname: Cho
authors.affiliation: Department of Paediatrics, Asan Medical Centre Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea.|Medical Genetics Centre, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Beom Hee
authors.initials: BH
authors.lastname: Lee
authors.affiliation: Medical Genetics Centre, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Gu-Hwan
authors.initials: GH
authors.lastname: Kim
authors.affiliation: Asan Institute for Life Sciences, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jin Ok
authors.initials: JO
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Eul Joo
authors.initials: EJ
authors.lastname: Seo
authors.affiliation: Department of Paediatrics, Asan Medical Centre Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Paediatrics, Asan Medical Centre Children's Hospital, University of Ulsan College of Medicine, Seoul, Korea.|Medical Genetics Centre, Asan Medical Centre, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Han-Wook
authors.initials: HW
authors.lastname: Yoo
mesh_terms: D000293:Adolescent; D002118:Calcium / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D019587:Dietary Supplements; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007011:Hypoparathyroidism / Q000097:blood / Q000188:drug therapy / Q000209:etiology* / Q000235:genetics*; D007223:Infant; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D012189:Retrospective Studies
chemical_list: D010281:Parathyroid Hormone; D002118:Calcium