China Nagano1, Naoya Morisada2,3, Kandai Nozu1, Koichi Kamei4, Ryojiro Tanaka5, Shoichiro Kanda6, Shinichi Shiona7, Yoshinori Araki8, Shinichiro Ohara9, Chieko Matsumura10, Katsuaki Kasahara11, Yukiko Mori12, Akane Seo13, Kenichiro Miura14, Miki Washiyama15, Keisuke Sugimoto16, Ryoko Harada17, Satoshi Tazoe18, Hiroyo Kourakata19, Mayumi Enseki20, Daisuke Aotani21, Takeshi Yamada22, Nana Sakakibara1, Tomohiko Yamamura1, Shogo Minamikawa1, Kenji Ishikura4,23, Shuichi Ito24, Motoshi Hattori14, Kazumoto Iijima1. 1. Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan. 2. Department of Pediatrics, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan. morisada@med.kobe-u.ac.jp. 3. Department of Clinical Genetics, Hyogo Prefectural Kobe Children's Hospital, 1-6-7, Minatojimaminami-machi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan. morisada@med.kobe-u.ac.jp. 4. Division of Nephrology and Rheumatology, National Center for Child Health and Development, 2-10-1 Okura, Setagaya-ku, Tokyo, 157-8535, Japan. 5. Department of Nephrology, Hyogo Prefectural Kobe Children's Hospital, 1-6-7 Minatojima Minamimachi, Chuo-ku, Kobe, Hyogo, 650-0047, Japan. 6. Department of Pediatrics, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. 7. Department of Pediatrics, Oita Prefectural Hospital, 476, Oaza-Bujyo, Oita, Oita, 870-8511, Japan. 8. Department of Pediatrics, Hokkaido Medical Center, 5-7-1-1 Yamanote Nishi-ku, Sapporo, Hokkaido, 063-0005, Japan. 9. Department of Pediatrics, Fukushima Medical University School of Medicine, 1 Hikarigaoka, Fukushima-shi, Fukushima, 960-1295, Japan. 10. Department of Pediatrics, National Hospital Organization Chibahigashi National Hospital, 673 Nitonacho, Chuo-ku, Chiba, Chiba, 260-8712, Japan. 11. Department of Pediatric Nephrology, Japanese Red Cross Nagoya Daini Hospital, 2-9 Myokencho, Syowa-ku, Nagoya, 4668-650, Japan. 12. Department of Pediatrics, Japanese Red Cross Fukui Hospital, 2-4-1, Tsukimi, Fukui, 918-8501, Japan. 13. Department of Diabetes and Endocrinology, Kobe University Hospital, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe, 650-0017, Japan. 14. Department of Pediatric Nephrology, Tokyo Women's Medical University, School of Medicine, 8-1, Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan. 15. Department of Diabetes and Endocrinology, Kusatsu General Hospital, 1660 Yabase-cho, Kusatsu, Siga, 525-8585, Japan. 16. Department of Pediatrics, Faculty of Medicine, Kindai University, 377-2, Ohno-Higashi, Osakasayama, Osaka, 589-8511, Japan. 17. Department of Nephrology, Tokyo Metropolitan Children's Medical Center, 2-8-29, Musashidai, Fuchu, Tokyo, 183-8561, Japan. 18. Department of Metabolism, Osaka City General Hospital, 2-13-22 Miyakojimahondori, Miyakojima-ku, Osaka, 534-0021, Japan. 19. Department of Respiratory Medicine, Niigata Saiseikai Sanjo Hospital, 6-18 Oonohata, Sanjyo-shi, Niigata, 955-8511, Japan. 20. Department of Pediatrics, Tokai University Hospital, 143, Shimokasuya, Isehara-shi, Tokyo, 259-1193, Japan. 21. Department of Gastroenterology and Metabolism, Graduate School of Medical Sciences and Medical School, Nagoya City University, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, 467-8601, Japan. 22. Department of Pediatrics, Niigata University School of Medicine, 1-757, Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan. 23. Department of Pediatrics, Kitasato University School of Medicine, 1-15-1, Kitasato, Minami-ku, Sagamihara, 252-0375, Japan. 24. Department of Pediatrics, Yokohama City University, 3-9, Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.
Abstract
BACKGROUND: Hepatocyte nuclear factor 1β (HNF1B), located on chromosome 17q12, causes renal cysts and diabetes syndrome (RCAD). Moreover, various phenotypes related to congenital anomalies of the kidney and urinary tract (CAKUT) or Bartter-like electrolyte abnormalities can be caused by HNF1B variants. In addition, 17q12 deletion syndrome presents with multi-system disorders, as well as RCAD. As HNF1B mutations are associated with different phenotypes and genotype-phenotype relationships remain unclear, here, we extensively studied these mutations in Japan. METHODS: We performed genetic screening of RCAD, CAKUT, and Bartter-like syndrome cases. Heterozygous variants or whole-gene deletions in HNF1B were detected in 33 cases (19 and 14, respectively). All deletion cases were diagnosed as 17q12 deletion syndrome, confirmed by multiplex ligation probe amplification and/or array comparative genomic hybridization. A retrospective review of clinical data was also conducted. RESULTS: Most cases had morphological abnormalities in the renal-urinary tract system. Diabetes developed in 12 cases (38.7%). Hyperuricemia and hypomagnesemia were associated with six (19.3%) and 13 cases (41.9%), respectively. Pancreatic malformations were detected in seven cases (22.6%). Ten patients (32.3%) had liver abnormalities. Estimated glomerular filtration rates were significantly lower in the patients with heterozygous variants compared to those in patients harboring the deletion (median 37.6 vs 58.8 ml/min/1.73 m2; p = 0.0091). CONCLUSION: We present the clinical characteristics of HNF1B-related disorders. To predict renal prognosis and complications, accurate genetic diagnosis is important. Genetic testing for HNF1B mutations should be considered for patients with renal malformations, especially when associated with other organ involvement.
BACKGROUND: Hepatocyte nuclear factor 1β (HNF1B), located on chromosome 17q12, causes renal cysts and diabetes syndrome (RCAD). Moreover, various phenotypes related to congenital anomalies of the kidney and urinary tract (CAKUT) or Bartter-like electrolyte abnormalities can be caused by HNF1B variants. In addition, 17q12 deletion syndrome presents with multi-system disorders, as well as RCAD. As HNF1B mutations are associated with different phenotypes and genotype-phenotype relationships remain unclear, here, we extensively studied these mutations in Japan. METHODS: We performed genetic screening of RCAD, CAKUT, and Bartter-like syndrome cases. Heterozygous variants or whole-gene deletions in HNF1B were detected in 33 cases (19 and 14, respectively). All deletion cases were diagnosed as 17q12 deletion syndrome, confirmed by multiplex ligation probe amplification and/or array comparative genomic hybridization. A retrospective review of clinical data was also conducted. RESULTS: Most cases had morphological abnormalities in the renal-urinary tract system. Diabetes developed in 12 cases (38.7%). Hyperuricemia and hypomagnesemia were associated with six (19.3%) and 13 cases (41.9%), respectively. Pancreatic malformations were detected in seven cases (22.6%). Ten patients (32.3%) had liver abnormalities. Estimated glomerular filtration rates were significantly lower in the patients with heterozygous variants compared to those in patients harboring the deletion (median 37.6 vs 58.8 ml/min/1.73 m2; p = 0.0091). CONCLUSION: We present the clinical characteristics of HNF1B-related disorders. To predict renal prognosis and complications, accurate genetic diagnosis is important. Genetic testing for HNF1B mutations should be considered for patients with renal malformations, especially when associated with other organ involvement.