Osteoprotegerin (OPG) is a circulating decoy receptor for RANKL, a multifunctional cytokine essential for the differentiation of tissue-specific cells in bone and immune systems such as osteoclasts, medullary thymic epithelial cells (mTECs), and intestinal microfold cells (M cells). However, it is unknown whether OPG functions only at the production site or circulates to other tissues acting in an endocrine fashion. Here we explore the cellular source of OPG by generating OPG-floxed mice and show that locally produced OPG, rather than circulating OPG, is crucial for bone and immune homeostasis. Deletion of OPG in osteoblastic cells leads to severe osteopenia without affecting serum OPG. Deletion of locally produced OPG increases mTEC and M cell numbers while retaining the normal serum OPG level. This study shows that OPG limits its functions within the tissue where it was produced, illuminating the importance of local regulation of the RANKL system.

Frasier syndrome is a rare inherited disease characterized by steroid-resistant nephrotic syndrome, gonadal tumor, and male pseudohermaphroditism (female external genitalia with sex chromosomes XY), which is based on a splice site mutation of Wilms tumor-suppressor gene 1 (WT1). Several unusual Frasier syndrome cases have been reported in which male pseudohermaphroditism was absent. We reviewed 88 Frasier syndrome cases in the literature and classified them into three types (type 1–3) according to external genitalia and sex chromosomes, and described their clinical phenotypes. Type 1 Frasier syndrome is characterized by female external genitalia with 46,XY (n = 72); type 2 by male external genitalia with 46,XY (n = 8); and type 3 by female external genitalia with 46,XX (n = 8). Clinical course differs markedly among the types. Although type 1 is noticed at the mean age of 16 due to mainly primary amenorrhea, type 2 and 3 do not present delayed secondary sex characteristics, making diagnosis difficult. The prevalence of gonadal tumor is high in type 1 (67%) and also found in 3 of the 8 type 2 cases, but not in any type 3 cases, which emphasize that preventive gonadectomy is unnecessary in type 3. On the basis of our findings, we propose a new diagnostic algorithm for Frasier syndrome. Cancer Prev Res; 8(4); 271–6. ©2015 AACR.

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In kidney transplantation, it is essential to avoid acute vascular complications, such as hemorrhage and renal vascular thrombosis, which may often lead to allograft loss. Inherited dysfibrinogenemia is a rare coagulation disorder with a wide spectrum of clinical manifestations, such as excessive bleeding and thrombosis. A 12-yr-old boy, previously diagnosed with renal hypodysplasia, was found to have reduced fibrinogen concentrations. Coagulation tests assessing surgical risk during kidney transplantation showed a discrepancy between functional and immunologic fibrinogen concentrations. Gene analysis confirmed inherited dysfibrinogenemia, with a heterozygous mutation in FGA (Aα Arg16His) in the patient and his mother. Based on the molecular and functional properties of the mutation, and a familial phenotype, in which his aunt had experienced a previous bleeding episode, the patient was considered at greater risk of bleeding than of thrombosis. The patient was administered fibrinogen concentrate before surgery, and kidney transplantation was performed with his father as the organ donor. The patient received additional prophylactic infusions of fibrinogen concentrate postoperatively, and his postoperative course was uneventful. Accurate diagnosis of dysfibrinogenemia, including gene analysis, is important for correctly managing patients with this coagulation disorder who are undergoing kidney transplantation.

<div>Abstract<p>Frasier syndrome is a rare inherited disease characterized by steroid-resistant nephrotic syndrome, gonadal tumor, and male pseudohermaphroditism (female external genitalia with sex chromosomes XY), which is based on a splice site mutation of Wilms tumor-suppressor gene 1 (<i>WT1</i>). Several unusual Frasier syndrome cases have been reported in which male pseudohermaphroditism was absent. We reviewed 88 Frasier syndrome cases in the literature and classified them into three types (type 1–3) according to external genitalia and sex chromosomes, and described their clinical phenotypes. Type 1 Frasier syndrome is characterized by female external genitalia with 46,XY (<i>n</i> = 72); type 2 by male external genitalia with 46,XY (<i>n</i> = 8); and type 3 by female external genitalia with 46,XX (<i>n</i> = 8). Clinical course differs markedly among the types. Although type 1 is noticed at the mean age of 16 due to mainly primary amenorrhea, type 2 and 3 do not present delayed secondary sex characteristics, making diagnosis difficult. The prevalence of gonadal tumor is high in type 1 (67%) and also found in 3 of the 8 type 2 cases, but not in any type 3 cases, which emphasize that preventive gonadectomy is unnecessary in type 3. On the basis of our findings, we propose a new diagnostic algorithm for Frasier syndrome. <i>Cancer Prev Res; 8(4); 271–6. ©2015 AACR</i>.</p></div>