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Mutations in TTC21B cause different phenotypes in two childhood cases in China
Author(s) -
Zhang Hongwen,
Su Baige,
Liu Xiaoyu,
Xiao Huijie,
Ding Jie,
Yao Yong
Publication year - 2018
Publication title -
nephrology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 61
eISSN - 1440-1797
pISSN - 1320-5358
DOI - 10.1111/nep.13008
Subject(s) - medicine , nephronophthisis , ciliopathy , congenital hepatic fibrosis , mutation , autosomal recessive polycystic kidney disease , pathology , compound heterozygosity , nephrotic syndrome , situs inversus , gene mutation , disease , phenotype , genetics , gene , portal hypertension , polycystic kidney disease , biology , cirrhosis
Aim The TTC21B gene is now known as causative of nephronophthisis‐related 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 next‐generation sequencing. Results The two cases 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 disease‐causing TTC21B mutations were identified. One case carried homozygous mutation c.2211 + 3A > G, while the other case carried compound heterozygous 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.