Novel clinical and genetic insights into Gitelman syndrome from 95 Chinese patients.

Abstract

Background: Gitelman syndrome (GS) is a rare tubulopathy with clinical and genetic heterogeneity. This study aimed to investigate the characteristics of Chinese GS patients.

Methods: The diagnosis of GS was established by combining clinical phenotypes with genetic testing, after which the clinical, biochemical, and genetic data were statistically analyzed.

Results: We reported 95 Chinese GS patients aged 2-52 years. The younger group (≤ 16 years) had more frequent febrile episodes (20.4% vs. 4.3%, P = 0.028) and nausea/vomiting (12.2% vs. 0.0%, P = 0.027) but fewer paresthesia/numbness (20.4% vs. 43.5%, P = 0.026) and palpitations (8.2% vs. 37.0%, P = 0.001), along with higher serum potassium and magnesium levels (2.86 ± 0.45 mmol/L vs. 2.67 ± 0.38 mmol/L, P = 0.034; 0.65 ± 0.14 mmol/L vs. 0.58 ± 0.16 mmol/L, P = 0.031) than the older group (> 16 years). Moreover, serum potassium and magnesium levels were positively correlated and both were negatively correlated with age. Additionally, Among 170 detected SLC12A3 variants, 73 distinct variants were identified, including six novel ones. The compound heterozygous group exhibited higher serum magnesium levels compared to the heterozygous and homozygous groups (0.65 ± 0.17 mmol/L vs. 0.56 ± 0.09 mmol/L, P = 0.015; 0.65 ± 0.17 mmol/L vs. 0.51 ± 0.07 mmol/L, P < 0.001). Age at diagnosis was associated with variant types.

Conclusion: The study characterized the phenotypic and genotypic features of Chinese GS patients, highlighting age and mutation genotype as key factors influencing phenotype, underscoring the importance of standardized potassium and magnesium supplementation, and expanding the known mutation spectrum with novel variants.