Clinical features and TTC21B genotype of a child with nephronophthisis type 12

• Published in: Zhongguo dang dai er ke za zhi Vol. 21; no. 6; p. 580
• Main Authors: Jian, Shan, Wei, Qi-Jiao, Liu, Yu-Tong, Wang, Wei, Zhou, Yu, Quan, Mei-Ying, He, Yan-Yan, Song, Hong-Mei, Wei, Min
• Format: Journal Article
• Language: Chinese
• Published: China 01.06.2019
• Subjects: Child, Preschool; Female; Genotype; Humans; Kidney; Kidney Diseases, Cystic; Kidney Failure, Chronic; Microtubule-Associated Proteins - genetics; Mutation; Nephrosis - genetics
• ISSN: 1008-8830

Nephronophthisis (NPHP) is a group of autosomal recessive tubulointerstitial cystic kidney disorders. This article reports a case of NPHP type 12 caused by TTC21B mutations. The girl had an insidious onset, with moderate proteinuria, renal dysfunction, stage 2 hypertension, situs inversus, and short phalanges when she visited the hospital for the first time at the age of 3 years and 6 months. The renal lesions progressed to end-stage renal disease (ESRD) before she was 4 years old. Urine protein electrophoresis showed glomerular proteinuria. There were significant increases in urinary β2-microglobulin and α1-microglobulin. Gene detection revealed two compound heterozygous mutations, c.1552T>C (p.C518R) and c.752T>G (p.M251R), in the TTC21B gene, which came from her father and mother respectively. The c.752T>G mutation was a novel mutation. It is concluded that besides typical tubular changes of NPHP, marked glomerular damage is also observed in patients with TTC21B gene mutations.