Turnover of mammal sex chromosomes in the Sry-deficient Amami spiny rat is due to male-specific upregulation of Sox9.

Mammalian sex chromosomes are highly conserved, and sex is determined by SRY on the Y chromosome. Two exceptional rodent groups in which some species lack a Y chromosome and Sry offer insights into how novel sex genes can arise and replace Sry, leading to sex chromosome turnover. However, intensive study over three decades has failed to reveal the identity of novel sex genes in either of these lineages. We here report our discovery of a male-specific duplication of an enhancer of Sox9 in the Amami spiny rat Tokudaia osimensis, in which males and females have only a single X chromosome (XO/XO) and the Y chromosome and Sry are completely lost. We performed a comprehensive survey to detect sex-specific genomic regions in the spiny rat. Sex-related genomic differences were limited to a male-specific duplication of a 17-kb unit located 430 kb upstream of Sox9 on an autosome. Hi-C analysis using male spiny rat cells showed the duplicated region has potential chromatin interaction with Sox9. The duplicated unit harbored a 1,262-bp element homologous to mouse enhancer 14 (Enh14), a candidate Sox9 enhancer that is functionally redundant in mice. Transgenic reporter mice showed that the spiny rat Enh14 can function as an embryonic testis enhancer in mice. Embryonic gonads of XX mice in which Enh14 was replaced by the duplicated spiny rat Enh14 showed increased Sox9 expression and decreased Foxl2 expression. We propose that male-specific duplication of this Sox9 enhancer substituted for Sry function, defining a novel Y chromosome in the spiny rat.

WT1 exon 10 missense variant in a pediatric patient with focal segmental glomerulosclerosis with embryonal hyperplasia.

A 6-year-old boy was diagnosed with chromosomal abnormalities (48,XYY, + 21[11]/46,XY[19]) at 4 months of age after a physical examination revealed an undescended testis and a dwarf penis. He also had mild renal dysfunction and severe proteinuria, and kidney biopsy at 2 years of age revealed focal segmental glomerulosclerosis. Genetic analysis to investigate suspected WT1 gene abnormalities revealed a novel variant in NM_024426.6:exon10:c.1506 T > A (p.(Asp502Glu)). His kidney function deteriorated rapidly, leading to the induction of peritoneal dialysis at 5 years of age. Although this variant had not been previously reported, bilateral nephrectomy was performed to prevent any progression of the tumor. Histopathology showed all the glomeruli observed within the observation area to be completely sclerotic, while also showing evidence of embryonal hyperplasia. This case was not a hot spot for Denys-Drash syndrome, but it had a similar phenotype and pathology that could have been derived from a WT1 gene abnormality.

Nail-patella syndrome with nephropathy in a de novo LMX1B mutation: triangular lunula of the thumb and lack of finger creases as clues.

Nail-patella syndrome (NPS) is an autosomal dominant disease caused mostly by mutations in the LMX1B gene and is characterized by hypoplastic nails, hypoplastic patella, elbow deformities, glaucoma, and nephropathy, sometimes leading to kidney failure. The combination and the severity of symptoms vary greatly from patient to patient. Because a kidney biopsy may show nonspecific findings, patients with nephropathy alone may not be diagnosed without undergoing genetic testing. We examined the case of a 6-year-old girl with persistent high proteinuria who was not diagnosed by kidney biopsy but had a diagnosis of a de novo mutation in the LMX1B gene following genetic testing. Retrospectively, only the thumbs showed triangular lunulae, while the third and fourth fingers lacked skin creases over the distal interphalangeal joints, which is subtle but characteristic of NPS. Notifying pediatric nephrologists of these findings can help avoid unnecessary kidney biopsies and lead to early detection of the disease.

Clinical and histological features in pediatric and adolescent/young adult patients with renal disease: a cross-sectional analysis of the Japan Renal Biopsy Registry (J-RBR).

BACKGROUND: Only a few studies have investigated epidemiological and clinicopathological information regarding pediatric and adolescent and young adult (AYA) patients with renal disease. The purpose of this study was to clarify the differences and relationship of clinicopathological findings between pediatric and AYA patients using the Japan Renal Biopsy Registry (J-RBR). METHODS: This cross-sectional study analyzed data from patients registered in the J-RBR between 2007 and 2017. Clinicopathological findings at diagnosis were analyzed for 3,463 pediatric (age < 15 years) and 6,532 AYA (age 15-30 years) patients. RESULTS: Although chronic nephritic syndrome was the most common clinical diagnosis at age > 5 years, nephrotic syndrome was the most frequent diagnosis at age < 4 years. The most common pathological diagnosis as classified by pathogenesis in pediatric patients was primary glomerular disease (except IgA nephropathy), whereas IgA nephropathy was increased in AYA patients. Mesangial proliferative glomerulonephritis was the most common pathological diagnosis as classified by histopathology in both pediatric and AYA patients. Minor glomerular abnormalities were the most frequent histopathologic diagnoses of nephrotic syndrome in childhood, but their frequency decreased with age. CONCLUSION: To the best of our knowledge, this is the first report of clinicopathological features of pediatric and AYA patients in a large nationwide registry of renal biopsy. There were differences of clinical, pathological and histopathologic findings between pediatric and AYA patients.

Analysis of mTOR pathway expression in lymphatic malformation and related diseases.

The mammalian target of rapamycin (mTOR) inhibitor sirolimus is an effective treatment for difficult-to-treat lymphatic anomalies. However, little is known about the expression of mTOR pathway components in lymphatic anomalies. Here we investigated the expression pattern of mTOR pathway components and their phosphorylated forms (mTOR, p-mTOR, 4EBP1, p-4EBP1, S6K1 and p-S6K1) in normal lymphatic vessels and lymphatic anomalies using immunohistochemistry. We studied 18 patients of lymphatic anomalies, including lymphatic malformation (LM, n = 14), Kaposiform lymphangiomatosis (KLA, n = 2) and Kaposiform hemangioendothelioma (KHE, n = 2). Normal lymphatic vessels expressed 4EBP1, S6K1 and p-S6K1, but not p-4EBP1, mTOR or p-mTOR. The mTOR was detected in all lymphatic anomalies, whereas its activation form p-mTOR was detected in half cases of KLA and KHE but not in LM. All lymphatic anomalies expressed S6K1 and its activated form p-S6K1. The expression of 4EBP1 was also found in all lymphatic anomalies, but its activation was detected in approximately half of them. The activation of mTOR was seen in tumor (KLA and KHE) but not in malformation (LM), whereas the activation of S6K1 and 4EBP1 was seen in all and half of lymphatic anomalies, respectively.

Japanese clinical practice guidelines for vascular anomalies 2017.

The objective was to prepare guidelines to perform the current optimum treatment by organizing effective and efficient treatments of hemangiomas and vascular malformations, confirming the safety, and systematizing treatment, employing evidence-based medicine (EBM) techniques and aimed at improvement of the outcomes. Clinical questions (CQs) were decided based on the important clinical issues. For document retrieval, key words for literature searches were set for each CQ and literature published from 1980 to the end of September 2014 was searched in Pubmed, Cochrane Library, and Japana Centra Revuo Medicina (JCRM). The strengths of evidence and recommendations acquired by systematic reviews were determined following the Medical Information Network Distribution System (MINDS) technique. A total of 33 CQs were used to compile recommendations and the subjects included efficacy of resection, sclerotherapy/embolization, drug therapy, laser therapy, radiotherapy, and other conservative treatment, differences in appropriate treatment due to the location of lesions and among symptoms, appropriate timing of treatment and tests, and pathological diagnosis deciding the diagnosis. Thus, the Japanese Clinical Practice Guidelines for Vascular Anomalies 2017 have been prepared as the evidence-based guidelines for the management of vascular anomalies.

Indications for tracheostomy in children with head and neck lymphatic malformation: analysis of a nationwide survey in Japan.

PURPOSE: Airway obstruction caused by lymphatic malformation (LM) in the head and neck may require a tracheostomy. We present the results of our analysis of a nationwide survey on the indications for tracheostomy in children with head and neck LM. METHODS: We analyzed data in relation to tracheostomy based on a questionnaire about 518 children with head and neck LM without mediastinal involvement. RESULTS: Tracheostomy was performed for 43 of the 518 children. Most (32/43) of these children were younger than 1 year of age and the tracheostomy was almost always performed for airway obstruction (40/43). The lesion was in contact with the airway in 32 (72%) of these children, but in only 58 (12%) of the 473 children who were managed without tracheostomy. When the maximum circumferential area of contact was compared, only 20 (27%) of 74 patients with maximum contact of less than a half-circle required tracheostomy, whereas 11 of 13 with maximum contact of more than a half-circle required tracheostomy (P = 0.0001). Six patients without airway contact required tracheostomy because of acute swelling caused by hemorrhage, infection, or both. CONCLUSIONS: Children with head and neck LM required tracheostomy to relieve airway obstruction. Tracheostomy should be considered if the lesion is in contact with the airway and surrounds more than a half-circle, and when it causes acute swelling.

Umbilical Cord Ulcer and Intrauterine Death in Fetal Intestinal Atresia.

OBJECTIVE: To examine the incidence of umbilical cord ulcer (UCU) that causes intrauterine fetal death (IUFD) in fetal duodenal or jejunoileal atresia and the association between UCU and bile acid concentrations in amniotic fluid. METHODS: Perinatal outcomes were evaluated in cases of fetal intestinal atresia between 2003 and 2017. A pathological examination of the umbilical cord was performed, and bile acid concentrations in the amniotic fluid were measured. RESULTS: Among the 46 cases included in this study, there were 27 with duodenal atresia and 19 with jejunoileal atresia. There were 4 cases (8.7%) of IUFD and 1 (2.2%) neonatal death with multiple structural anomalies. UCUs were found in 37.5% (15/40) of cases, and severe UCUs with exposed vessels were significantly more common in IUFD (3/4) than in livebirth (0/42) cases (p < 0.01). The incidences of chromosomal abnormality and structural anomalies were not markedly different between livebirth (9/30 and 11/42, respectively) and IUFD (1/3 and 1/4, respectively) cases. Bile acid concentrations in amniotic fluid were significantly higher in cases of UCUs than in those without (p < 0.01). CONCLUSION: UCUs were not rare in fetal intestinal atresia and were associated with high bile acid concentrations in amniotic fluid. UCUs with exposed vessels were associated with IUFD in intestinal atresia.

Treatment of mediastinal lymphatic malformation in children: an analysis of a nationwide survey in Japan.

PURPOSE: Clinical guidelines on lymphatic malformation (LM) influencing the airway have been crafted in the Research Project for Intractable Diseases. We herein report an analysis of a nationwide survey of mediastinal LM and the therapeutic recommendations. METHODS: Eighty-seven registered cases with mediastinal involvement were analyzed with a review of the literature. RESULTS: Mediastinal LM was located more often in the upper and anterior mediastinum and was found without any accompanying symptoms in 56/87 cases. Tracheostomy was required in 23/87 cases, mostly < 2 years of age (87%). All patients who needed tracheostomy had a lesion in contact with the airway, while only 55% of those without tracheostomy had contact. Tracheostomy tended to be placed more when the longer segment of the airway was in contact with the LM. Multimodal treatments were performed in 29 patients, but the lesions remained in most cases, and chylothorax, hemorrhaging, nerve palsy, and infections were noted as complications. CONCLUSIONS: In patients with mediastinal LM, tracheostomy may be necessary, especially when the lesion is extensive and contacts the airway. Extirpation of the mediastinal LM may be the only therapeutic option, but in cases with few or no symptoms, non-surgical treatment should be considered in light of potential postoperative complications.

Monocyte Chemoattractant Protein-1 (MCP-1) as a Potential Therapeutic Target and a Noninvasive Biomarker of Liver Fibrosis Associated With Transient Myeloproliferative Disorder in Down Syndrome.

Liver fibrosis is one of the common complications of transient myeloproliferative disorder (TMD) in Down syndrome (DS), but the exact molecular pathogenesis is largely unknown. We herein report a neonate of DS with liver fibrosis associated with TMD, in which we performed the serial profibrogenic cytokines analyses. We found the active monocyte chemoattractant protein-1 expression in the affected liver tissue and also found that both serum and urinary monocyte chemoattractant protein-1 concentrations are noninvasive biomarkers of liver fibrosis. We also showed a prospective of the future anticytokine therapy with herbal medicine for the liver fibrosis associated with TMD in DS.

Prolonged tacrolimus for pediatric gastrointestinal disorder: Double-edged sword?

BACKGROUND: Although tacrolimus (TAC) can induce remission in children with refractory inflammatory bowel disease (IBD) or autoimmune gastroenteropathy (AGE), its use in maintenance therapy remains controversial. The aim of this study was to investigate the potential nephrotoxic nature of prolonged TAC use. METHODS: This retrospective study reviewed children with gastrointestinal disorder who underwent kidney biopsy for the evaluation of renal damage during TAC therapy for >1 year. The clinical and histological features of renal damage were evaluated in this single-institution cohort. RESULTS: Eighteen of 121 children with IBD and two children with AGE followed at a national children hospital in Tokyo, Japan, received TAC between August 2006 and April 2013. Among them, five (Crohn's disease, n = 3; autoimmune gastropathy, n = 1; autoimmune enteropathy, n = 1) received TAC for >1 year, and underwent kidney biopsy. All five had achieved remission on TAC, but had histological evidence of chronic nephrotoxicity. Renal damage in one patient with relatively low TAC trough level remained mild. Estimated glomerular filtration rate (eGFR) at the time of kidney biopsy was lower than at the initiation of TAC in all four available patients. Among them, eGFR improved in one patient after the decrease or discontinuation of TAC. CONCLUSIONS: TAC appeared to be effective in children with refractory gastrointestinal disorder, but long-term use seems to cause irreversible renal damage. Rigorous monitoring of eGFR and kidney biopsy in selected cases should be considered for the proper adjustment of TAC.

Chronic histiocytic intervillositis in three consecutive pregnancies in a single patient: Differing clinical results and pathology according to treatment used.

Chronic histiocytic intervillositis (CHI) is an extremely rare pathological condition but is strongly associated with severe obstetric complications and has a high recurrence rate. The management of this condition has not yet been established. We describe herein the occurrence of CHI in the late second-third trimester in each of three consecutive pregnancies in a single patient with four previous consecutive early miscarriages. In this patient, each of the three complicated pregnancies was managed with one of the following, respectively: low-dose aspirin; heparin plus low-dose aspirin; and prednisolone plus low-dose aspirin. CHI was histologically confirmed in all three pregnancies, but the clinical results and pathology (e.g. extent of histiocytic infiltration) in each pregnancy clearly differed with treatment. Both combination treatments eventuated in a live birth. Immunosuppressive therapy seemed to produce better clinical results by restricting the extent of the affected areas. The elevated alkaline phosphatase associated with the CHI was assumed to have no clinical prognostic value.

Gorham-Stout Disease of the Skull Base With Hearing Loss: Dramatic Recovery and Antiangiogenic Therapy.

Gorham-Stout disease (GSD) is a rare disorder of unknown etiology. We present a 6-year-old male with GSD involving the skull base who presented with recurrent cerebrospinal fluid (CSF) rhinorrhea, severe hearing loss, and facial palsy secondary to cerebellar herniation into the internal auditory canal. After 2 months of treatment with pegylated interferon (IFN) α-2b (50 µg/week), his hearing recovered dramatically. Two years later, new bone formation appeared radiologically and IFN was switched to sirolimus. One year after the switch, CSF rhinorrhea disappeared. Antiangiogenic therapy might inhibit proliferation of vascular endothelial cells in osteolytic lesions and lead to new bone formation.

Clinical Features and Prognosis of Generalized Lymphatic Anomaly, Kaposiform Lymphangiomatosis, and Gorham-Stout Disease.

BACKGROUND: Complex lymphatic anomalies are intractable lymphatic disorders, including generalized lymphatic anomaly (GLA), Gorham-Stout disease (GSD), and kaposiform lymphangiomatosis (KLA). The etiology of these diseases remains unknown and diagnosis is confused by their similar clinical findings. This study aimed to clarify the differences in clinical features and prognosis among GLA, KLA, and GSD, in Japanese patients. PROCEDURE: Clinical features, radiological and pathological findings, treatment, and prognosis of patients were obtained from a questionnaire sent to 39 Japanese hospitals. We divided the patients into three groups according to radiological findings of bone lesions and pathology. Differences in clinical findings and prognosis were analyzed. RESULTS: Eighty-five patients were registered: 35 GLA, 9 KLA, and 41 GSD. Disease onset was more common in the first two decades of life (69 cases). In GSD, osteolytic lesions were progressive and consecutive. In GLA and KLA, 18 patients had osteolytic lesions that were multifocal and nonprogressive osteolysis. Thoracic symptoms, splenic involvement, and ascites were more frequent in GLA and KLA than in GSD. Hemorrhagic pericardial and pleural effusions were more frequent in KLA than GLA. GSD had a significantly favorable outcome compared with combined GLA and KLA (P = 0.0005). KLA had a significantly poorer outcome than GLA (P = 0.0268). CONCLUSIONS: This survey revealed the clinical features and prognosis of patients with GLA, KLA, and GSD. Early diagnosis and treatment of KLA are crucial because KLA has high mortality. Further prospective studies to risk-stratify complex lymphatic anomalies and optimize management for KLA are urgently needed.

Significant improvement in Fabry disease podocytopathy after 3 years of treatment with agalsidase beta.

BACKGROUND: Fabry disease is an X-linked lysosomal disorder caused by decreased activity of α-galactosidase A (GLA). Consequent accumulation of globotriaosylceramide (GL-3) in lysosomes results in damage to a variety of organs, including the kidneys. Enzyme replacement therapy (ERT) is an effective treatment, but whether it should be started before organ damage is evident is a matter of debate. CASE DIAGNOSIS/TREATMENT: A 10-year-old boy who complained of severe sole pain for 3 years had been misdiagnosed with juvenile idiopathic arthritis. Further investigations revealed decreased GLA activity and a M1T mutation in the GLA gene causing protein truncation, suggestive of Fabry disease. Despite normal renal function and urinalysis, renal biopsy showed abnormal structure, with marked accumulation of GL-3 in podocytes, partial effacement of foot processes and irregularly reduced expression of nephrin in the slit diaphragm. After 1 year of ERT with 1 mg/kg agalsidase beta once every 2 weeks, his pain had resolved with ERT combined with carbamazepine and pregabalin. After 3 years of the ERT, repeat biopsy showed little renal GL-3 deposition, resolution of foot process effacement, and a dramatic improvement in nephrin expression. CONCLUSIONS: There may be a window of opportunity in which pain and renal injury can be addressed in the early stages of Fabry disease. Early initiation of ERT should therefore be considered for children with Fabry disease.

Novel Nonsense Mutation in the NLRP7 Gene Associated with Recurrent Hydatidiform Mole.

AIM: This study aimed to clarify the genetic and epigenetic features of recurrent hydatidiform mole (RHM) in Japanese patients. METHODS: Four Japanese isolated RHM cases were analyzed using whole-exome sequencing. Villi from RHMs were collected by laser microdissection for genotyping and DNA methylation assay of differentially methylated regions (DMRs). Single nucleotide polymorphisms of PEG3 and H19 DMRs were used to confirm the parental origin of the variants. RESULTS: A novel homozygous nonsense mutation in NLRP7 (c.584G>A; p.W195X) was identified in 1 patient. Genotyping of one of her molar tissue revealed that it was biparental but not androgenetic in origin. Despite the fact that the RHM is biparental, maternally methylated DMRs of PEG3, SNRPN and PEG10 showed complete loss of DNA methylation. A paternally methylated DMR of H19 retained normal methylation. CONCLUSIONS: This is the first Japanese case of RHM with a novel homozygous nonsense NLRP7 mutation and a specific loss of maternal DNA methylation of DMRs. Notably, the mutation was identified in an isolated case of an ethnic background that has not previously been studied in this context. Our data underscore the involvement of NLRP7 in RHM pathophysiology and confirm that DNA methylation of specific regions is critical.

Use of serial assessment of disease severity and liver biopsy for indication for liver transplantation in pediatric Epstein-Barr virus-induced fulminant hepatic failure.

The decision to perform liver transplantation (LT) in patients with Epstein-Barr virus (EBV)-induced fulminant hepatic failure (FHF) relies on a precise assessment of laboratory and pathological findings. In this study, we analyzed clinical and laboratory data as well as the pathological features of the liver in order to evaluate the pathogenesis and the need for LT in 5 patients with EBV-induced FHF. According to the King's College criteria, the Acute Liver Failure Early Dynamic (ALFED) model, and the Japanese criteria (from the Acute Liver Failure Study Group of Japan), only 1 patient was considered to be a candidate for LT. However, explanted liver tissues in 3 cases exhibited massive hepatocellular necrosis together with diffuse CD8-positive T cell infiltration in both the portal area and the sinusoid. EBV was detected in the liver, plasma, and peripheral blood mononuclear cells (PBMNCs). In 2 cases indicated to be at moderate risk by the ALFED model, liver biopsy showed CD8-positive and EBV-encoded RNA signal-positive lymphocytic infiltration predominantly in the portal area, but massive hepatocellular necrosis was not observed. These patients were treated with immunosuppressants and etoposide under the diagnosis of EBV-induced hemophagocytic lymphohistiocytosis or systemic EBV-positive T cell lymphoproliferative disease of childhood. EBV DNA was detected at a high level in PBMNCs, although it was negative in plasma. On the basis of the pathological analysis of the explanted liver tissues, LT was proposed for the restoration of liver function and the removal of the EBV-infected lymphocytes concentrated in the liver. Detecting EBV DNA by a quantitative polymerase chain reaction in plasma and PBMNCs was informative. An accurate evaluation of the underlying pathogenesis is essential for developing a treatment strategy in patients with EBV-induced FHF.