Primary hyperparathyroidism in Chinese children and adolescents: A single-centre experience at Peking Union Medical College Hospital.

Objective: Primary hyperparathyroidism (PHPT) in children is thought to be extremely rare. Our study aimed to summarize the clinical characteristics and the molecular genetics in patients with paediatric PHPT in China.

Design: Retrospective observational study.

Methods: A total of 59 paediatric PHPT patients (onset age <18 years) admitted to Peking Union Medical College Hospital from 1975 to 2015 were retrospectively identified. A group of 118 adult PHPT patients who presented during the same period were selected for comparing clinical characteristics between the two groups. Germline mutation analyses of the MEN1, CDC73, RET, CDKN1B and CaSR genes were performed in 24 patients.

Results: Only one paediatric patient (1.7%) with PHPT was asymptomatic. Bone involvement, urolithiasis, acute pancreatitis and hypercalcaemic crisis were present in 86.4%, 39.0%, 6.8% and 10.2% of cases, respectively. Paediatric PHPT presented more commonly with rickets/osteomalacia compared to adult PHPT. Fifty-seven paediatric patients underwent surgery. Adenoma, hyperplasia, atypical adenoma and carcinoma occurred in 80.7%, 10.5%, 7.0% and 1.8% of cases, respectively. Of the 24 paediatric patients screened for genetic mutations, two patients were found to carry MEN1 mutations and six were found to carry CDC73 mutations. The mutation rate was 22.2% (4/18) in sporadic patients.

Conclusion: Unlike adults with PHPT, most paediatric PHPT were symptomatic. Rickets/osteomalacia was more common in paediatric patients than in their adult counterparts. Paediatric PHPT patients can be treated successfully with surgical intervention. Genetic screening of the MEN1 and CDC73 genes for mutations should be recommended in paediatric patients due to a relatively high mutation rate.