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Aim: The TTC21B gene is now known as causative of nephronophthisisrelated ciliopathies (NPHP-RC).We reported two Chinese paediatric cases with end-stage renal disease and other phenotypes caused by the TTC21B gene mutations. Methods: The clinical features of Chinese paediatric cases with NPHP-RC were summarized. Mutation analysis of the TTC21B gene was performed using nextgeneration sequencing. Results: The twocases both had nephrotic proteinuria, renal failure, hypertension and abnormal liver function (or hepatic fibrosis). One case also presented situs inversus and short phalanges. They developed end-stage renal disease (ESRD) at 1 year old and 8 years old, respectively, when renal pathology both showed focal segmental glomerular sclerosis (FSGS) with tubulointerstitial lesions including interstitial fibrosis and atrophic tubules. Three novel diseasecausing TTC21B mutations were identified. One case carried homozygous mutation c.2211 +3A>G,while the other case carried compoundheterozygous mutations c.1552 T > C (p.C518R) and c.1456dupA (p.R486KfsX22). Conclusion: Mutations in TTC21B cause a range of ciliopathy phenotypes in humans. We identified 3 novel TTC21B mutations in two Chinese paediatric cases that both presented end-stage renal disease and other different features. This is the first TTC21B mutations ever reported in China. [ABSTRACT FROM AUTHOR]