Abstract: Objective To investigate the clinical manifestations of a case of congenital nephrogenic diabetes insipidus (CNDI) caused by AVPR2 gene variation with urinary tract dilatation and growth hormone deficiency. Methods The clinical data of a child with CNDI with urinary tract dilation and growth hormone deficiency and the results of genetic testing in his family were retrospectively analyzed. Results A boy, aged 10 years and 11 months, presented with polydipsia, polyuria and growth retardation since childhood. The boy was diagnosed with nephrogenic diabetes insipidus, urinary tract dilatation, and growth hormone deficiency through growth hormone stimulation tests and related examinations. Gene test showed that the missense variation of C.347 (exon2) A>T (P.k116m) in the second exon of AVPR2 gene was a new variant, which was not detected in the peripheral blood of the child's parents and elder brother, and the child was diagnosed as CNDI. Conclusion The main pathogenic gene of CNDI is AVPR2 gene, and CNDI can be developed with urinary tract dilation and short stature.

Key words: congenital nephrogenic diabetes insipidus; AVPR 2 gene; urinary tract dilation; growth hormone deficiency