Isao Hozumi1, Hisaka Kurita2, Kazuhiro Ozawa3, Nobuyuki Furuta4, Masatoshi Inden2, Shin-Ichiro Sekine2, Megumi Yamada5, Yuichi Hayashi5, Akio Kimura5, Takashi Inuzuka5, Mitsuru Seishima4. 1. Laboratory of Medical Therapeutics and Molecular Therapeutics, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan. Electronic address: hozumi@gifu-pu.ac.jp. 2. Laboratory of Medical Therapeutics and Molecular Therapeutics, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan. 3. Nursing Collaboration Center, Gifu College Nursing, 3047-1, Hashima, Gifu 501-6295, Japan. 4. Department of Informative Clinical Medicine, Gifu University, Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan. 5. Department of Neurology and Geriatrics, Gifu University, Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
Abstract
INTRODUCTION: Idiopathic basal ganglia calcification (IBGC), also called Fahr's disease or recently primary familial brain calcification (PFBC), is characterized by abnormal deposits of minerals including calcium mainly and phosphate in the brain. Mutations in SLC20A2 (IBGC1 (merged with former IBGC2 and IBGC3)), which encodes PiT-2, a phosphate transporter, is the major cause of IBGC. Recently, Slc20a2-KO mice have been showed to have elevated levels of inorganic phosphorus (Pi) in cerebrospinal fluid (CSF); however, CSF Pi levels in patients with IBGC have not been fully examined. METHODS: We investigated the cases of 29 patients with IBGC including six patients with SLC20A2 mutation and three patients with PDGFB mutation, and 13 controls. The levels of sodium (Na), potassium (K), chloride (Cl), calcium (Ca), and Pi in sera and CSF were determined by potentiometry and colorimetry. Moreover, clinical manifestations were investigated in the IBGC patients with high Pi levels in CSF. RESULTS: The study revealed that the average level of Pi in the CSF of the total group of patients with IBGC is significantly higher than that of the control group, and the levels of Pi in CSF of the IBGC patients with SLC20A2 mutations are significantly higher than those of the IBGC patients with PDGFB mutations, the other IBGC patients and controls. CONCLUSION: Results of this study suggest that the levels of CSF Pi will be a good biomarker for IBGC1.
INTRODUCTION:Idiopathic basal ganglia calcification (IBGC), also called Fahr's disease or recently primary familial brain calcification (PFBC), is characterized by abnormal deposits of minerals including calcium mainly and phosphate in the brain. Mutations in SLC20A2 (IBGC1 (merged with former IBGC2 and IBGC3)), which encodes PiT-2, a phosphate transporter, is the major cause of IBGC. Recently, Slc20a2-KO mice have been showed to have elevated levels of inorganic phosphorus (Pi) in cerebrospinal fluid (CSF); however, CSF Pi levels in patients with IBGC have not been fully examined. METHODS: We investigated the cases of 29 patients with IBGC including six patients with SLC20A2 mutation and three patients with PDGFB mutation, and 13 controls. The levels of sodium (Na), potassium (K), chloride (Cl), calcium (Ca), and Pi in sera and CSF were determined by potentiometry and colorimetry. Moreover, clinical manifestations were investigated in the IBGCpatients with high Pi levels in CSF. RESULTS: The study revealed that the average level of Pi in the CSF of the total group of patients with IBGC is significantly higher than that of the control group, and the levels of Pi in CSF of the IBGCpatients with SLC20A2 mutations are significantly higher than those of the IBGCpatients with PDGFB mutations, the other IBGCpatients and controls. CONCLUSION: Results of this study suggest that the levels of CSF Pi will be a good biomarker for IBGC1.