Multi-centre study of the clinical features and gene variant spectrum of Gitelman syndrome in Chinese children.

Based on the Chinese Children Genetic Kidney Disease Database (CCGKDD), we established a pediatric Gitelman syndrome (GS) cohort to explore the phenotype and genotype characteristics. Thirty-two patients with SLC12A3 gene variants were collected. Five cases (16%) were homozygous, 16 (50%) were compound heterozygous, 10 (31%) carried only a single variant, and the other one harbored two de novo variants beyond classification. p.(T60M) was found in eight patients. The average diagnosis age was 7.79 ± 3.54 years. A total of 31% of the patients were asymptomatic. Muscle weakness was the most common symptom, accounting for 50%. Earlier age of onset (4.06 ± 1.17 yr vs. 8.10 ± 3.46 yr vs. 8.61 ± 3.56 yr, p< 0.05) and lower urinary calcium-creatinine ratio (p = 0.024) were found in the homozygous group than those in the heterozygous and compound heterozygous group. Patients with p.(T60M) variant had an earlier age of onset (4.01 ± 2.83 yr vs. 6.92 ± 3.07 yr, p = 0.025) and lower urinary calcium-creatinine ratio (p = 0.056). Thus, more than 30% of GS children have no clinical symptoms. Homozygous variant and the p.(T60M) variant may be associated with earlier onset and lower urinary calcium excretion in Chinese pediatric GS.