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Thesaurismosis or storage diseases are rare genetic disorders due to an abnormal accumulation of an organic compound or its metabolite within cells. These conditions are either secondary to a defect in catabolism caused by enzymatic dysfunction or to a deficiency in transport proteins. They encompass lysosomal storage diseases, lipid storage diseases or dyslipidemias, and glycogen storage disorders or glycogenoses. Diagnosis is typically based on clinical and biological anomalies but may be made or suggested by the pathologist when symptoms are atypical or when biochemical or genetic tests are challenging to interpret. For accurate diagnosis, it is crucial to freeze a portion of the samples. Special staining and electronic microscopy can also aid in the diagnostic process. As the diagnosis is multidisciplinary, collaboration with clinicians, biochemists and geneticists is essential., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

Congenital anomalies of the kidney and urinary tract (CAKUT) accounts for up to 30% of antenatal congenital anomalies and is the main cause of kidney failure in children worldwide. This review focuses on practical approaches to CAKUT, particularly those with insufficient or abnormal nephron development, such as renal dysplasia, renal hypoplasia, and renal tubular dysgenesis. The review provides insights into the histological features, pathogenesis, mechanisms, etiologies, antenatal and postnatal presentation, management, and prognosis of these anomalies. Differential diagnoses are discussed as several syndromes may include CAKUT as a phenotypic component and renal dysplasia may occur in some ciliopathies, tumor predisposition syndromes, and inborn errors of metabolism. Diagnosis and genetic counseling for CAKUT are challenging, due to the extensive variability in presentation, genetic and phenotypic heterogeneity, and difficulties to assess postnatal lung and renal function on prenatal imaging. The review highlights the importance of perinatal autopsy and pathological findings in surgical specimens to establish the diagnosis and prognosis of CAKUT. The indications and the type of genetic testing are discussed. The aim is to provide essential insights into the practical approaches, diagnostic processes, and genetic considerations offering valuable guidance for pediatric and perinatal pathologists., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

An exome sequencing strategy employed to identify pathogenic variants in patients with pediatric-onset systemic lupus or Evans syndrome resulted in the discovery of six novel monoallelic mutations in PTPN2. PTPN2 is a phosphatase that acts as an essential negative regulator of the JAK/STAT pathways. All mutations led to a loss of PTPN2 regulatory function as evidenced by in vitro assays and by hyperproliferation of patients' T cells. Furthermore, patients exhibited high serum levels of inflammatory cytokines, mimicking the profile observed in individuals with gain-of-function mutations in STAT factors. Flow cytometry analysis of patients' blood cells revealed typical alterations associated with autoimmunity and all patients presented with autoantibodies. These findings further supported the notion that a loss of function in negative regulators of cytokine pathways can lead to a broad spectrum of autoimmune manifestations and that PTPN2 along with SOCS1 haploinsufficiency constitute a new group of monogenic autoimmune diseases that can benefit from targeted therapy., (© 2024 Jeanpierre et al.)

Introduction: Acute fetal leukemia is rare and characterized by a very poor prognosis. The aims of this study were to identify cases of acute fetal leukemia and to describe ultrasound and fetopathological findings that should lead to a suspicion of this diagnosis, as well as the investigations required to confirm it., Methods: A national retrospective study was conducted. Clinical data, prenatal ultrasounds and postmortem findings of fetal acute leukemia cases were collected and analyzed., Results: We collected seven cases: four in utero fetal deaths, two neonatal deaths and one termination of pregnancy. Prenatal ultrasounds showed fetal hydrops (42.9%) associated with hepatosplenomegaly (100%). In addition, post-mortem examination (n = 6) suggested a Down syndrome in one case and showed other organomegaly (83.3%) due to blastic infiltration, mainly in the liver, along with extrahepatic multivisceral hematopoiesis. Immunostainings allowed to specify the type of leukemia (71.4%). In one case, diagnosis was made on blood smear and flow cytometry was performed on fresh blood samples. All cases corresponded to acute myeloid leukemia. Karyotype was abnormal in 4 cases (66.7%), including one free trisomy 21, two mosaic trisomy 21 and one chromosome 15 deletion. GATA1 gene mutations were identified in two cases: one mosaic trisomy 21 and one with normal karyotype., Conclusion: Any hepatosplenomegaly associated with fetal hydrops and a negative immune, infectious, and metabolic work-up, should suggest acute fetal leukemia and prompt additional investigations., (© 2024 John Wiley & Sons Ltd.)

Optimizing graft preservation is key for ex-situ split grafts in pediatric liver transplantation (PSLT). Hypothermic Oxygenated Perfusion (HOPE) improves ischemia-reperfusion injury (IRI) and post-operative outcomes in adult LT. This study compares the use of HOPE in ex-situ partial grafts to static cold storage ex-situ partial grafts (SCS-Split) and to the gold standard living donor liver transplantation (LDLT). All consecutive HOPE-Split, SCS-Split and LDLT performed between 2018-2023 for pediatric recipients were included. Post-reperfusion syndrome (PRS, drop ≥30% in systolic arterial pressure) and reperfusion biopsies served as early indicators of IRI. We included 47 pediatric recipients (15 HOPE-Split, 17 SCS-Split, and 15 LDLT). In comparison to SCS-Split, HOPE-Split had a significantly shorter cold ischemia time (CIT) (470min vs. 538 min; p =0.02), lower PRS rates (13.3% vs. 47.1%; p = 0.04) and a lower IRI score (3 vs. 4; p = 0.03). The overall IRI score (3 vs. 3; p = 0.28) and PRS (13.3% vs. 13.3%; p = 1) after HOPE-Split were comparable to LDLT, despite a longer CIT (470 min vs. 117 min; p < 0.001). Surgical complications, one-year graft, and recipient survival did not differ among the groups. In conclusion, HOPE-Split mitigates early IRI in pediatric recipients in comparison to SCS-Split, approaching the gold standard of LDLT., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Rossignol, Muller, Ruiz, Collardeau-Frachon, Boulanger, Depaulis, Antonini, Dubois, Mohkam and Mabrut.)

Glycogen storage disease type IV (GSD IV), also called Andersen disease, or amylopectinosis, is a highly heterogeneous autosomal recessive disorder caused by a glycogen branching enzyme (GBE, 1,4-alpha-glucan branching enzyme) deficiency secondary to pathogenic variants on GBE1 gene. The incidence is evaluated to 1:600 000 to 1:800 000 of live births. GBE deficiency leads to an excessive deposition of structurally abnormal, amylopectin-like glycogen in affected tissues (liver, skeletal muscle, heart, nervous system, etc.). Diagnosis is often guided by histological findings and confirmed by GBE activity deficiency and molecular studies. Severe neuromuscular forms of GSD IV are very rare and of disastrous prognosis. Identification and characterization of these forms are important for genetic counseling for further pregnancies. Here we describe clinical, histological, enzymatic, and molecular findings of 10 cases from 8 families, the largest case series reported so far, of severe neuromuscular forms of GSD IV along with a literature review. Main antenatal features are: fetal akinesia deformation sequence or arthrogryposis/joint contractures often associated with muscle atrophy, decreased fetal movement, cystic hygroma, and/or hydrops fetalis. If pregnancy is carried to term, the main clinical features observed at birth are severe hypotonia and/or muscle atrophy, with the need for mechanical ventilation, cardiomyopathy, retrognathism, and arthrogryposis. All our patients were stillborn or died within 1 month of life. In addition, we identified five novel GBE1 variants., (© 2023 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM.)

Competing Interests: The authors declare that they have no conflict of interest.

Competing Interests: Disclosures None.

Introduction: Biological disease-modifying anti-rheumatic drugs (bDMARDs) targeting interleukin (IL)-6 and IL-1β represent a steroid-sparing first-line therapy used in systemic-onset juvenile idiopathic arthritis (sJIA). Recently, the occurrence of pulmonary alveolar proteinosis (PAP) in sJIA patients was reported with early-onset and exposure to bDMARDs as potential risk factors. We report on a new case with longitudinal immunomonitoring successfully treated by Janus Kinase inhibitors (JAKi) and review past clinical descriptions of this new entity., Methods: We report one case of pulmonary alveolar proteinosis and macrophage activation syndrome (PAP-MAS) with longitudinal immunomonitoring. We then conducted a review of the literature of seven publications reporting 107 cases of PAP-MAS sJIA, and included the main characteristics and evolution under treatment., Results: Of the seven articles analyzed, the incidence of PAP-MAS among sJIA patients varied from 1.28% to 12.9%. We report here a single case among a cohort of 537 sJIA patients followed in the pediatric department of the Hospices Civils de Lyon over the last 15 years. This child presented with all clinical and immunological characteristics of PAP-MAS. After several lines of treatment, he benefited from JAKi and improved with respect to both systemic symptoms and lung disease. In the literature, strategies with monoclonal antibodies targeting either INF-γ or IL-1β/IL-18 have been tested with variable results. Orally taken JAKi presents the advantage of targeting multiple cytokines and avoiding parenteral injections of monoclonal antibodies that may contribute to the pathogenesis., Conclusions: JAKi represent a promising option in the treatment of lung disease associated with sJIA.

Background: The role of protocol liver biopsies (PLB) in the follow-up of pediatric liver transplant recipients remains questionable. This single-center retrospective study aimed to evaluate their clinical impact on the long-term management of pediatric liver transplant recipients., Methods: We described histopathological lesions and clinical consequences for patient management of PLB performed 1, 5, 10, 15, 20, and 25 years after pediatric liver transplantation (LT)., Results: A total of 351 PLB performed on 133 patients between 1992 and 2021 were reviewed. PLB found signs of rejection in 21.7% of cases (76/351), and moderate to severe fibrosis in 26.5% of cases (93/351). Overall, 264 PLB (75.2%) did not cause any changes to patient care. Immunosuppression was enhanced after 63 PLB, including 23 cases of occult rejection. The 1-year PLB triggered significantly more changes, while biopsies at 15, 20, and 25 years produced the lowest rates of subsequent modifications. PLB had a significantly higher probability of inducing therapeutic changes if the patient had abnormal biological or imaging results (odds ratio [OR] 2.82 and 2.06), or a recent history of rejection or bacterial infection (OR 2.22 and 2.03)., Conclusion: Our results suggest that, although it often does not prompt any treatment changes, PLB could be performed because of its ability to detect silent rejection requiring an increase in immunosuppression. PLB could be carried out 1, 5, and 10 years after LT and then every 10 years in patients with normal biological and imaging results and no recent complications, while other patients could be kept on a 5-year protocol., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background and Objectives: To test the long-term ability of human ovarian cortex cells to develop in unconventional culture conditions. Materials and Methods. Ovarian cortex cells from fetuses aged 23 to 39 weeks gestation were cultured for 90 days in hollow chitosan hydrogel micro-bioreactors and concurrently in traditional wells. Various cell-type counts were considered. Results : With intact follicles as a denominator, the percentage of growing intact follicles at Day 0 varied widely between ovaries (0 to 31.7%). This percentage tended to increase or stay relatively constant in bioreactor as in control cultures; it tended more toward an increase over time in bioreactor vs. control cultures. Modeled percentages showed differences (though not significant) in favor of bioreactor cultures (16.12% difference at D50 but only 0.12% difference at D90). With all follicles present as a denominator, the percentage of growing primary and secondary follicles at D0 varied widely between ovaries (0 to 29.3%). This percentage tended to increase over time in bioreactor cultures but to decrease in control cultures. Modeled percentages showed significant differences in favor of bioreactor cultures (8.9% difference at D50 and 11.1% difference at D90). At D50 and D90, there were only few and sparse apoptotic cells in bioreactor cultures vs. no apoptotic cells in control cultures. Conclusions : Over three months, bioreactor folliculogenesis outperformed slightly traditional culture. This is an interesting perspective for follicle preservation and long-term toxicological studies.

Partial liver grafts from ex situ splitting are considered marginal due to prolonged static cold storage. The use of ex situ hypothermic oxygenated perfusion (HOPE) may offer a strategy to improve preservation of ex situ split grafts. In this single-center pilot study, we prospectively performed ex situ liver splitting during HOPE (HOPE-Split) for adult and pediatric partial grafts over a 1-year period (November 1, 2020 to December 1, 2021). The primary safety endpoint was based on the number of liver graft-related adverse events (LGRAEs) per recipient, including primary nonfunction, biliary complications, hepatic vascular complications, and early relaparotomies and was compared with consecutive single-center standard ex situ split transplantations (Static-Split) performed from 2018 to 2020. Secondary endpoints included preservation characteristics and early outcomes. Sixteen consecutive HOPE-Split liver transplantations (8 HOPE-Split procedures) were included and compared with 24 Static-Splits. All HOPE-Split grafts were successfully transplanted, and no graft loss nor recipient death was encountered during the median follow-up of 7.5 months (interquartile range, 5.5-12.5). Mean LGRAE per recipient was similar in both groups (0.31 ± 0.60 vs. 0.46 ± 0.83; p = 0.78) and split duration was not significantly increased for HOPE-Split (216 vs. 180 min; p = 0.45). HOPE-Split grafts underwent perfusion for a median of 125 min, which significantly shortened static cold storage (472 vs. 544 min; p = 0.001), whereas it prolonged total ex vivo preservation (595 vs. 544 min; p = 0.007) and reduced neutrophil infiltration on reperfusion biopsies (p = 0.04) compared with Static-Split. This clinical pilot study presents first feasibility and safety data for transplantation of partial liver grafts undergoing ex situ split during HOPE and suggests improved preservation compared with static ex situ splitting. These preliminary results will allow to set up large-scale trials on the use of machine perfusion in pediatric and split-liver transplantation., (© 2022 American Association for the Study of Liver Diseases.)

Background: Observations of vertical transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection from mother to fetus have recently been described in the literature. However, the consequences of such transmission, whether fetal or neonatal, are poorly understood., Methods: From a case of in utero fetal death at 24+2 weeks of gestation that occurred 7 days after the diagnosis of symptomatic SARS-CoV-2 infection in the mother, we isolated the incriminating virus by immunochemistry and molecular techniques in several fetal tissues, with a variant analysis of the SARS-CoV-2 genome., Results: The fetal demise could be explained by the presence of placental histological lesions, such as histiocytic intervillositis and trophoblastic necrosis, in addition to fetal tissue damage. We observed mild fetal growth retardation and visceral damage to the liver, causing hepatocellular damage and hemosiderosis. To the best of our knowledge, this is the first report in the literature of fetal demise secondary to maternal-fetal transmission of SARSCoV- 2 with a congenital infection and a pathological description of placental and fetal tissue damage., Conclusions: SARS-CoV-2 was identified in both specimens using 3 independent techniques (immunochemistry, real-time quantitative polymerase chain reaction, and realtime digital polymerase chain reaction). Furthermore, the incriminating variant has been identified., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Context.—: Perinatal death is an increasingly important problem as the coronavirus disease 2019 (COVID-19) pandemic continues, but the mechanism of death has been unclear., Objective.—: To evaluate the role of the placenta in causing stillbirth and neonatal death following maternal infection with COVID-19 and confirmed placental positivity for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)., Design.—: Case-based retrospective clinicopathologic analysis by a multinational group of 44 perinatal specialists from 12 countries of placental and autopsy pathology findings from 64 stillborns and 4 neonatal deaths having placentas testing positive for SARS-CoV-2 following delivery to mothers with COVID-19., Results.—: Of the 3 findings constituting SARS-CoV-2 placentitis, all 68 placentas had increased fibrin deposition and villous trophoblast necrosis and 66 had chronic histiocytic intervillositis. Sixty-three placentas had massive perivillous fibrin deposition. Severe destructive placental disease from SARS-CoV-2 placentitis averaged 77.7% tissue involvement. Other findings included multiple intervillous thrombi (37%; 25 of 68) and chronic villitis (32%; 22 of 68). The majority (19; 63%) of the 30 autopsies revealed no significant fetal abnormalities except for intrauterine hypoxia and asphyxia. Among all 68 cases, SARS-CoV-2 was detected from a body specimen in 16 of 28 cases tested, most frequently from nasopharyngeal swabs. Four autopsied stillborns had SARS-CoV-2 identified in internal organs., Conclusions.—: The pathology abnormalities composing SARS-CoV-2 placentitis cause widespread and severe placental destruction resulting in placental malperfusion and insufficiency. In these cases, intrauterine and perinatal death likely results directly from placental insufficiency and fetal hypoxic-ischemic injury. There was no evidence that SARS-CoV-2 involvement of the fetus had a role in causing these deaths.

Technological advances in both genome sequencing and prenatal imaging are increasing our ability to accurately recognize and diagnose Mendelian conditions prenatally. Phenotype-driven early genetic diagnosis of fetal genetic disease can help to strategize treatment options and clinical preventive measures during the perinatal period, to plan in utero therapies, and to inform parental decision-making. Fetal phenotypes of genetic diseases are often unique and at present are not well understood; more comprehensive knowledge about prenatal phenotypes and computational resources have an enormous potential to improve diagnostics and translational research. The Human Phenotype Ontology (HPO) has been widely used to support diagnostics and translational research in human genetics. To better support prenatal usage, the HPO consortium conducted a series of workshops with a group of domain experts in a variety of medical specialties, diagnostic techniques, as well as diseases and phenotypes related to prenatal medicine, including perinatal pathology, musculoskeletal anomalies, neurology, medical genetics, hydrops fetalis, craniofacial malformations, cardiology, neonatal-perinatal medicine, fetal medicine, placental pathology, prenatal imaging, and bioinformatics. We expanded the representation of prenatal phenotypes in HPO by adding 95 new phenotype terms under the Abnormality of prenatal development or birth (HP:0001197) grouping term, and revised definitions, synonyms, and disease annotations for most of the 152 terms that existed before the beginning of this effort. The expansion of prenatal phenotypes in HPO will support phenotype-driven prenatal exome and genome sequencing for precision genetic diagnostics of rare diseases to support prenatal care., (© 2022 The Authors. American Journal of Medical Genetics Part C: Seminars in Medical Genetics published by Wiley Periodicals LLC.)

Encephalocraniocutaneous lipomatosis (ECCL) or Haberland syndrome (MIM #613001) is a rare congenital neurocutaneous disorder. It is characterized by unilateral ocular, cutaneous and central nervous system anomalies. Key clinical features include hairless fatty tissue nevus of the scalp, choristoma of the eye and intraspinal and intracerebral lipomas. We report one of the first cases diagnosed after termination of pregnancy at 35 WG, including antenatal and post-mortem imaging, complete autopsy and genetic analysis. Prenatal ultrasound and MRI of the third trimester showed multifocal spinal lesions and left lateral cerebral ventriculomegaly with cerebral atrophy. Diagnosis of ECCL was suggested at complete autopsy which revealed nevus psiloliparus of the scalp, facial hamartomas and intracranial and spinal lipomas. In addition, our case also exhibited a cardiac rhabdomyoma and a multicystic dysplastic kidney, both never reported to date in this syndrome. ECCL was confirmed by the identification of a postzygotic FGFR1 mutation. We reviewed the literature and discuss the pathogenesis of this syndrome.

Neonatal collodion baby or ichthyosis can pose a diagnostic challenge, and in many cases, only additional organ involvement or the course of the disease will help differentiate between non-syndromic and syndromic forms. Skin abnormalities are described in about 20% of the congenital disorders of glycosylation (CDG). Among those, some rare CDG forms constitute a special group among the syndromic ichthyoses and can initially misdirect the diagnosis towards non-syndromic genodermatosis. DOLK-CDG is such a rare subtype, resulting from a defect in dolichol kinase, in which the congenital skin phenotype (often ichthyosis) is later associated with variable extracutaneous features such as dilatative cardiomyopathy, epilepsy, microcephaly, visual impairment, and hypoglycemia and may lead to a fatal course. We report two neonatal cases of lethal ichthyosis from the same family, with distal digital constrictions and a progressive course leading to multi-organ failure and death. Postmortem trio whole-exome sequencing revealed the compound heterozygous variants NM&#95;014908.3: c.1342G>A, p.(Gly448Arg) and NM&#95;014908.3: c.1558A>G, p.(Thr520Ala) in the DOLK gene in the first affected child, which were confirmed in the affected sibling. Reduced staining with anti-α-Dystroglycan antibody was observed in frozen heart tissue of the second child as an expression of reduced O-mannosylation due to the dolichol kinase deficiency. In addition to the detailed dermatopathological changes, both cases presented hepatic and extrahepatic hemosiderosis on histological examination. Our patients represent an early and fatal form of DOLK-CDG with a striking presentation at birth resembling severe collodion baby. Both cases emphasize the phenotypic variability of glycosylation disorders and the importance to broaden the differential diagnosis of ichthyosis and to actively search for organ involvement in neonates with ichthyosis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Komlosi, Claris, Collardeau-Frachon, Kopp, Hausser, Mazereeuw-Hautier, Jonca, Zimmer, Sanlaville and Fischer.)

The NLRC4 inflammasome is part of the human immune innate system. Its activation leads to the cleavage of pro-inflammatory cytokines IL-1β and IL-18, promoting inflammation. NLRC4 gain-of-function (GOF) mutations have been associated with early-onset recurrent fever, recurrent macrophagic activation syndrome and enterocolitis. Herein, we describe two new patients with NLRC4 mutations. The first case presented with recurrent fever and vasoplegic syndrome, gut symptoms and urticarial rashes initially misdiagnosed as a severe protein-induced enterocolitis syndrome. The second case had recurrent macrophage activation syndrome (MAS) and shock, suggesting severe infection. We identified two NLRC4 mutations, on exon 4, within the nucleotide-binding protein domain (NBD). After a systematic review of NLRC4 GOF mutations, we highlight the wide spectrum of this disease with a limited genotype-phenotype correlation. Vasoplegic shock was only reported in patients with mutation in the NBD. Diagnosing this new entity combined with gastrointestinal symptoms and vasoplegic shocks is challenging. It mimics severe allergic reaction or sepsis. The plasma IL-18 level and genetic screening are instrumental to make a final diagnosis.

Introduction: Pregnant women with covid-19 are more likely to experience preterm birth. The virus seems to be associated with a wide range of placental lesions, none of them specific., Method: We collected cases of Covid-19 maternal infection during pregnancy associated with poor pregnancy outcomes, for which we received the placenta. We studied clinical data and described pathological findings of placenta and post-mortem examination of fetuses. We performed an immunohistochemical study and RT-PCR of SARS-Cov-2 on placenta samples., Results: We report 5 cases of poor fetal outcome, 3 fetal deaths and 2 extreme premature neonates, one with growth restriction, without clinical and biological sign of SARS-Cov-2 infection. All placenta presented massive perivillous fibrin deposition and large intervillous thrombi associated with strong SARS-Cov-2 expression in trophoblast and SARS-CoV-2 PCR positivity in amniotic fluid or on placenta samples. Chronic histiocytic intervillositis was present in 4/5 cases. Placental ultrasound was abnormal and the sFLT1-PIGF ratio was increased in one case. Timing between mothers' infection and the poor fetal outcome was ≤10 days in 4 cases. The massive placental damage are directly induced by the virus whose receptors are expressed on trophoblast, leading to trophoblast necrosis and massive inflammation in villous chamber, in a similar way it occurs in diffuse alveolar damage in adults infected by SARS-Cov-2., Discussion: SARS-Cov-2 can be associated to a rare set of placental lesions which can lead to fetal demise, preterm birth, or growth restriction. Stronger surveillance of mothers infected by SARS-Cov-2 is required., Competing Interests: Declaration of competing interest None., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Abstract: Familial intestinal hypocholesterolemias, such as abetalipoproteinemia, hypobetalipoproteinemia, and chylomicron retention disease, are rare genetic diseases that result in a defect in the synthesis or secretion of lipoproteins containing apolipoprotein B.In children, these conditions present with diarrhoea and growth failure, whereas adults present with neuromuscular, ophthalmological, and hepatic symptoms. Simple laboratory investigations have shown that diagnosis can be made from findings of dramatically decreased cholesterol levels, deficiencies in fat-soluble vitamins (mostly vitamin E), endoscopic findings of the characteristic white intestinal mucosa, and fat-loaded enterocytes in biopsy samples. Genetic analysis is used to confirm the diagnosis. Treatment is based on a low-fat diet with essential fatty acid supplementation, high doses of fat-soluble vitamins, and regular and life-long follow-up.The present study examines cases and literature findings of these conditions, and emphasises the need to explore severe hypocholesterolemia and deficiencies in fat-soluble vitamins to not miss these rare, but easy to diagnose and treat, disorders., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Purpose: Molecular diagnosis based on singleton exome sequencing (sES) is particularly challenging in fetuses with multiple congenital abnormalities (MCA). Indeed, some studies reveal a diagnostic yield of about 20%, far lower than in live birth individuals showing developmental abnormalities (30%), suggesting that standard analyses, based on the correlation between clinical hallmarks described in postnatal syndromic presentations and genotype, may underestimate the impact of the genetic variants identified in fetal analyses., Methods: We performed sES in 95 fetuses with MCA. Blind to phenotype, we applied a genotype-first approach consisting of combined analyses based on variants annotation and bioinformatics predictions followed by reverse phenotyping. Initially applied to OMIM-morbid genes, analyses were then extended to all genes. We complemented our approach by using reverse phenotyping, variant segregation analysis, bibliographic search and data sharing in order to establish the clinical significance of the prioritised variants., Results: sES rapidly identified causal variant in 24/95 fetuses (25%), variants of unknown significance in OMIM genes in 8/95 fetuses (8%) and six novel candidate genes in 6/95 fetuses (6%)., Conclusions: This method, based on a genotype-first approach followed by reverse phenotyping, shed light on unexpected fetal phenotype-genotype correlations, emphasising the relevance of prenatal studies to reveal extreme clinical presentations associated with well-known Mendelian disorders., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Background & Aims: A single point mutation in the Z-variant of alpha 1-antitrypsin (Z-AAT) alone can lead to both a protein folding and trafficking defect, preventing its exit from the endoplasmic reticulum (ER), and the formation of aggregates that are retained as inclusions within the ER of hepatocytes. These defects result in a systemic AAT deficiency (AATD) that causes lung disease, whereas the ER-retained aggregates can induce severe liver injury in patients with ZZ-AATD. Unfortunately, therapeutic approaches are still limited and liver transplantation represents the only curative treatment option . To overcome this limitation, a better understanding of the molecular basis of ER aggregate formation could provide new strategies for therapeutic intervention., Methods: Our functional and omics approaches here based on human hepatocytes from patients with ZZ-AATD have enabled the identification and characterisation of the role of the protein disulfide isomerase (PDI) A4/ERP72 in features of AATD-mediated liver disease., Results: We report that 4 members of the PDI family (PDIA4, PDIA3, P4HB, and TXNDC5) are specifically upregulated in ZZ-AATD liver samples from adult patients. Furthermore, we show that only PDIA4 knockdown or alteration of its activity by cysteamine treatment can promote Z-AAT secretion and lead to a marked decrease in Z aggregates. Finally, detailed analysis of the Z-AAT interactome shows that PDIA4 silencing provides a more conducive environment for folding of the Z mutant, accompanied by reduction of Z-AAT-mediated oxidative stress, a feature of AATD-mediated liver disease., Conclusions: PDIA4 is involved in AATD-mediated liver disease and thus represents a therapeutic target for inhibition by drugs such as cysteamine. PDI inhibition therefore represents a potential therapeutic approach for treatment of AATD., Lay Summary: Protein disulfide isomerase (PDI) family members, and particularly PDIA4, are upregulated and involved in alpha 1-antitrypsin deficiency (AATD)-mediated liver disease in adults. PDI inhibition upon cysteamine treatment leads to improvements in features of AATD and hence represents a therapeutic approach for treatment of AATD-mediated liver disease., Competing Interests: The authors have no potential conflicts (financial, professional, or personal) relevant to the manuscript. Please refer to the accompanying ICMJE disclosure forms for further details., (© 2021 The Authors.)

Although a rare disease, bilateral congenital anomalies of the kidney and urinary tract (CAKUT) are the leading cause of end stage kidney disease in children. Ultrasound-based prenatal prediction of postnatal kidney survival in CAKUT pregnancies is far from accurate. To improve prediction, we conducted a prospective multicenter peptidome analysis of amniotic fluid spanning 140 evaluable fetuses with CAKUT. We identified a signature of 98 endogenous amniotic fluid peptides, mainly composed of fragments from extracellular matrix proteins and from the actin binding protein thymosin-β4. The peptide signature predicted postnatal kidney outcome with an area under the curve of 0.96 in the holdout validation set of patients with CAKUT with definite endpoint data. Additionally, this peptide signature was validated in a geographically independent sub-cohort of 12 patients (area under the curve 1.00) and displayed high specificity in non-CAKUT pregnancies (82 and 94% in 22 healthy fetuses and in 47 fetuses with congenital cytomegalovirus infection respectively). Change in amniotic fluid thymosin-β4 abundance was confirmed with ELISA. Knockout of thymosin-β4 in zebrafish altered proximal and distal tubule pronephros growth suggesting a possible role of thymosin β4 in fetal kidney development. Thus, recognition of the 98-peptide signature in amniotic fluid during diagnostic workup of prenatally detected fetuses with CAKUT can provide a long-sought evidence base for accurate management of the CAKUT disorder that is currently unavailable., (Copyright © 2021 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)

Background: Vaginal lesions are rare and of various types in children. Clinical presentation is generally undifferenciated. Histological examination is fundamental to ascertain the nature of the lesion. Regarding tumoral lesions, histological subtypes encountered are radically different from those seen in adults, dominated by stromal benign lesions., Objective: The aim of this retrospective study was to describe characteristics and pathological aspects of pediatric vaginal lesions, diagnosed in a single pediatric experienced center., Study Design: A database analysis was performed on all vaginal samples of patients under 18 years old received in a pediatric-specialized pathology laboratory of an academic hospital, over a 26-year period., Results: Among 36 vaginal tissue samples reported, a total of 15 tumoral or pseudotumoral processes was recorded. Primitive malignant tumors included embryonal rhabdomyosarcoma (n = 3) and germ-cell tumors, yolk-sac type (n = 2). Benign tumoral or pseudotumoral processes included inflammatory stromal polyps (n = 8), epidermic cyst (n = 1), and benign Müllerian papilloma (n = 1)., Discussion: Over 15 primitive vaginal tumors, 1/3 was malignant with embryonal rhabdomyosarcoma being the most common. The remaining 2/3 specimens were benign, with stromal inflammatory lesions being the most commonly observed. Fibro-epithelial polyp is a debated entity, which covers a wide histological spectrum, with varying inflammation and stromal cellularity, raising sometimes the question of the differential diagnosis with rhabdomyosarcoma. Stromal cells morphology along with their immunohistochemical profile suggest their reactive myofibroblastic nature. Pseudotumoral inflammatory lesions display very similar histological findings with these entities. A common pathogenesis beginning with an inflammatory process, potentially accelerated by chronic traumatic factors, could be discussed., Conclusion: We confirmed the rarity and the diversity of vaginal lesions in children. Vaginoscopy and biopsy sample should be systematic, given the non-specific presentation of tumoral processes. Myogenin immunostain must be systematic in case of vaginal polypoid mass, in order to rule out malignancy., Competing Interests: Conflict of interest The Authors declare that there is no conflict of interest., (Copyright © 2020 Journal of Pediatric Urology Company. Published by Elsevier Ltd. All rights reserved.)