TY - JOUR A2 - Shiozawa, Yusuke AU - Namatame-Ohta, Noriko AU - Morikawa, Shuntaro AU - Nakamura, Akie AU - Matsuo, Kumihiro AU - Nakajima, Masahide AU - Tomizawa, Kazuhiro AU - Tanahashi, Yusuke AU - Tajima, Toshihiro PY - 2018 DA - 2018/07/03 TI - Four Japanese Patients with Congenital Nephrogenic Diabetes Insipidus due to the AVPR2 Mutations SP - 6561952 VL - 2018 AB - Almost 90% of nephrogenic diabetes insipidus (NDI) is caused by mutations in the arginine vasopressin receptor 2 gene (AVPR2) on the X chromosome. Herein, we reported clinical and biochemical parameters in four cases of three unrelated Japanese families and analyzed the status of the AVPR2. Two of the four patients had poor weight gain. However, in the male and female sibling cases, neither had poor weight gain while toddlers, but in the male sibling, episodes of recurrent fever, polyuria, and polydipsia led to the diagnosis of NDI at 4 years of age. Analysis of AVPR2 identified two nonsense mutations (c.299_300insA; p.K100KfsX91 and c.296G > A; p.W99X) and one missense mutation (c.316C > T; p.R106C). These mutations were previously reported. The patient with c.316C > T; p.R106C had milder symptoms consistent with previous reports. Of the familial cases, the sister was diagnosed as having NDI, but a skewed X-inactivation pattern in her peripheral blood lymphocytes was not identified. In conclusion, our study expands the spectrum of phenotypes and characterized mutations in AVPR2 in NDI. SN - 2090-6803 UR - https://doi.org/10.1155/2018/6561952 DO - 10.1155/2018/6561952 JF - Case Reports in Pediatrics PB - Hindawi KW - ER -