Clinical and genetic characteristics of hypoparathyroidism in children: a multicenter experience in China.

Objective: This study was aimed to analyze the clinical and genetic characteristics of hypoparathyroidism in children.

Methods: We performed a retrospective analysis of 74 patients diagnosed with pediatric hypoparathyroidism from 2014 to 2023, recruited in five medical centers across China. Data of basic information and clinical tests were extracted from patients' records. Whole-exome sequencing (WES), multiplex ligation-dependent probe amplification (MLPA), and chromosomal microarray analysis (CMA) were utilized to identify the genetic causes.

Results: The results indicated a median onset age of 6.07 ± 4.82 years and a median diagnosis age of 6.91 ± 4.88 years. Of the 46 patients who underwent genetic tests, 35 were found to carry pathogenic variants related to hypoparathyroidism. Specifically, 19 cases (19/46, 41.30%) had 22q11.2 microdeletion, while other variations included AIRE (8/46, 17.39%), GATA3 (3/46, 6.52%), CaSR (2/46, 4.34%), and the rest 3 patients with mutations of TBCE, PTH and mitochondrial gene deletion respectively. Convulsions were the most common initial presentation, observed in 43 cases. The non-DGS group exhibited the lowest serum PTH levels compared to DiGeorge syndrome and gene-negative group. Among the 66 patients who underwent cranial CT or MR, 26 (26/66, 39.99%) presented with intracranial calcification.

Conclusions: We reported the largest cohort of childhood hypoparathyroidism with genetic diagnoses, reinforcing the view that genetic disorders account for the majority of pediatric hypoparathyroidism, with the 22q11.2 microdeletion being the most prevalent. Identifying the genetic causes of hypoparathyroidism is crucial for predicting patient outcomes, managing comorbidities, and, importantly, informing decisions regarding the potential use of emerging recombinant human PTH therapy.