Heterozygosity for loss-of-function variants in LZTR1 is associated with isolated multiple café-au-lait macules.

PURPOSE: Pathogenic LZTR1 variants cause schwannomatosis and dominant/recessive Noonan syndrome (NS). We aim to establish an association between heterozygous loss-of-function (LoF) LZTR1 alleles and isolated multiple café-au-lait macules (CaLMs). METHODS: 849 unrelated participants with multiple CaLMs, lacking pathogenic/likely pathogenic NF1 and SPRED1 variants, underwent RASopathy gene panel sequencing. Data on 125 individuals with heterozygous LZTR1 variants were collected for characterizing their clinical features and the associated molecular spectrum. In vitro functional assessment was performed on a representative panel of missense variants and small in-frame deletions. RESULTS: Analysis revealed heterozygous LZTR1 variants in 6.0% (51/849) of participants, exceeding the general population prevalence. LZTR1-related CaLMs varied in number, displayed sharp or irregular borders, and were generally isolated, but occasionally associated with features recurring in RASopathies. In two families, CaLMs and schwannomas co-occurred. The molecular spectrum mainly consisted of truncating variants, indicating LoF. These variants substantially overlapped with those occurring in schwannomatosis and recessive NS. Functional characterization showed accelerated protein degradation or mislocalization, and failure to downregulate MAPK signaling. CONCLUSION: Our findings expand the phenotypic variability associated with LZTR1 variants, which, in addition to conferring susceptibility to schwannomatosis and causing dominant and recessive NS, occur in individuals with isolated multiple CaLMs.

Transient erythroblastopenia of childhood after COVID-19 infection: a case report.

BACKGROUND: Transient erythroblastopenia of childhood (TEC) is an acquired, self-limited pure red cell aplasia that usually occurs in children 4 years old and younger. This clinical condition has been priorly described to be linked to numerous viral and immunologic mechanisms. COVID-19, caused by the coronavirus SARS-CoV-2, was initially discovered in China in December 2019. The disease quickly spread worldwide, resulting in pandemic. CASE PRESENTATION: This manuscript reports a new clinically relevant condition associated to COVID-19, describing a child with clinical and biochemical signs of Pure Red Blood cells aplasia and complete absence of erythroblasts at the bone marrow needle aspiration with signs of erythrophagocytosis, resembling morphological signs such as in hemophagocytic lymphohistiocytosis (HLH), temporally associated to SARS-CoV-2 infection. CONCLUSION: This report highlights a newly described continuum laboratory and clinical spectrum of immune/hematological dysregulations secondary to SARS-CoV-2. SARS-CoV-2 infection-linked TEC has never been described in literature, but, according to our findings, should be considered in all the patients with transient erythroblastopenia without congenital red blood cell abnormalities and serology negative for major infections associated with TEC. This condition must be considered in the same spectrum of MIS-C and the inter-links among the two clinical manifestations, as well as a potential interdependence among them, should be considered in the future.

Healthcare migration in Italian paediatric haematology-oncology centres belonging to AIEOP.

BACKGROUND: In Italy, there is a network of centres headed by the Italian Association of Pediatric Hematology and Oncology (AIEOP) for the diagnosis and treatment of paediatric cancers on almost the entire national territory. Nevertheless, migration of patients in a hospital located in a region different from that of residence is a widespread habit, sometimes motivated by several reasons. The aim of this paper is to assess the impact of migration of children with cancer to AIEOP centres in order to verify their optimal distribution throughout the national territory. METHODS: To this purpose, we used information on 41,205 registered cancer cases in the database of Mod.1.01 Registry from AIEOP centres, with age of less than 20 years old at diagnosis, diagnosed from 1988 to 2017. Patients' characteristics were analysed and compared using the X2 or Fisher's exact test or Mann-Whitney test, when appropriate. Survival distributions were estimated using the method of Kaplan and Meier, and the log-rank test was used to examine differences among subgroups. RESULTS: Extra-regional migration involved overall 19.5% of cases, ranging from 23.3% (1988-1997) to 16.4% (2008-2017) (p < 0.001). In leukaemias and lymphomas we observed a mean migration of 8.8% overall, lower in the North (1.2%) and Centre (7.8%) compared to the South & Isles (32.3%). In the case of solid tumours, overall migration was 25.7%, with 4.2% in the North, 17.2% in the Centre and 59.6% in the South & Isles. For regions with overall levels of migration higher than the national average, most migration cases opted for AIEOP centres of close or even neighbouring regions. Overall survival at 10 years from diagnosis results 69.9% in migrants vs 78.3% in no migrants (p < 0.001). CONCLUSIONS: There is still a certain amount of domestic migration, the causes of which can be easily identified: migration motivated by a search for high specialization, migration due to lack of local facilities, or regions in which no AIEOP centres are present, which makes migration obligatory. Better coordination between AIEOP centres could help to reduce so-called avoidable migration, but technical and political choices will have to be considered, with the active participation of sector technicians.

The diagnostic and therapeutic challenge of atrial flutter in children: a case report.

BACKGROUND: Palpitations represent a common cause for consultation in the pediatric Emergency Department (ED). Unlike adults, palpitations in children are less frequently dependent from the heart, recognizing other causes. CASE PRESENTATION: A 11-year-old male came to our pediatric ED for epigastric pain, vomiting and palpitations. During the previous 6 month the patient was affected by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus). Electrocardiogram (ECG) revealed supraventricular tachycardia. Therefore, adenosine was administered unsuccessfully. The administration of adenosine, however, allowed us to make diagnosis of atypical atrial flutter. Multiple attempts at both electrical cardioversion, transesophageal atrial overdrive, and drug monotherapy were unsuccessful in our patient. Consequently, a triple therapy with amiodarone, flecainide, and beta-blocker was gradually designed to control the arrhythmic pattern with the restoration of a left upper atrial rhythm. There was not any evidence of sinus rhythm in the patient clinical history. CONCLUSIONS: The present study underlines the rarity of this type of dysrhythmia in childhood and the difficulties in diagnosis and management, above all in a patient who has never showed sinus rhythm. Raising awareness of all available treatment options is essential for a better management of dysrhythmia in children.

Recommendations for the management of acute immune thrombocytopenia in children. A Consensus Conference from the Italian Association of Pediatric Hematology and Oncology.

BACKGROUND: Immune thrombocytopenia (ITP) is an acquired immune-mediated bleeding disorder characterized by isolated thrombocytopenia. Its estimated yearly incidence in the pediatric population is 1.9-6.4/100,000. ITP in children is usually a self-limiting and benign disorder. The clinical management of children with ITP often remains controversial, as robust randomized trials on the management of this disorder are lacking. Treatments vary widely in clinical practice and existing guidelines from hematology societies on clinical management offer indications based largely on expert opinion rather than strong evidence. MATERIALS AND METHODS: The Coagulative Disorder Working Group of the Italian Association of Pediatric Hematology and Oncology (AIEOP) developed this document to collect shared expert opinions on the management of newly diagnosed ITP, updating previous guidelines and providing recommendations to pediatricians. Each statement has been given a score expressing the strength of evidence, appropriateness and agreement among participants. RESULTS: Clear-cut definitions of the clinical phases of the disease and clinical response are stated. Recommendations are given regarding the classification of bleeding symptoms, evaluation of bleeding risk, diagnosis, and prognostic factors. Specific recommendations for treatment include indications for first-line (intravenous immunoglobulins, steroids) and second-line (combined therapy, thrombopoietin receptor agonists, immunosuppressive drugs, rituximab) therapeutic agents, as well as hemorrhagic emergency and supportive treatment, including emergency splenectomy. The optimal follow-up schedule, the relation between ITP and vaccines and health-related quality-of-life issues are also discussed. DISCUSSION: The panel achieved broad consensus on issues related to how to treat children with newly diagnosed ITP, providing a comprehensive review of all relevant clinical aspects.

Genome editing and cancer therapy: handling the hypoxia-responsive pathway as a promising strategy.

The precise characterization of oxygen-sensing pathways and the identification of pO2-regulated gene expression are both issues of critical importance. The O2-sensing system plays crucial roles in almost all the pivotal human processes, including the stem cell specification, the growth and development of tissues (such as embryogenesis), the modulation of intermediate metabolism (including the shift of the glucose metabolism from oxidative to anaerobic ATP production and vice versa), and the control of blood pressure. The solid cancer microenvironment is characterized by low oxygen levels and by the consequent activation of the hypoxia response that, in turn, allows a complex adaptive response characterized mainly by neoangiogenesis and metabolic reprogramming. Recently, incredible advances in molecular genetic methodologies allowed the genome editing with high efficiency and, above all, the precise identification of target cells/tissues. These new possibilities and the knowledge of the mechanisms of adaptation to hypoxia suggest the effective development of new therapeutic approaches based on the manipulation, targeting, and exploitation of the oxygen-sensor system molecular mechanisms.

Neurofibromatosis Type 1: Pediatric Aspects and Review of Genotype-Phenotype Correlations.

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition, with a birth incidence of approximately 1:2000-3000, caused by germline pathogenic variants in NF1, a tumor suppressor gene encoding neurofibromin, a negative regulator of the RAS/MAPK pathway. This explains why NF1 is included in the group of RASopathies and shares several clinical features with Noonan syndrome. Here, we describe the main clinical characteristics and complications associated with NF1, particularly those occurring in pediatric age. NF1 has complete penetrance and shows wide inter- and intrafamilial phenotypic variability and age-dependent appearance of manifestations. Clinical presentation and history of NF1 are multisystemic and highly unpredictable, especially in the first years of life when penetrance is still incomplete. In this scenario of extreme phenotypic variability, some genotype-phenotype associations need to be taken into consideration, as they strongly impact on genetic counseling and prognostication of the disease. We provide a synthetic review, based on the most recent literature data, of all known genotype-phenotype correlations from a genetic and clinical perspective. Molecular diagnosis is fundamental for the confirmation of doubtful clinical diagnoses, especially in the light of recently revised diagnostic criteria, and for the early identification of genotypes, albeit few, that correlate with specific phenotypes.

Neuropsychiatric Manifestations, Reduced Self-Esteem and Poor Quality of Life in Children and Adolescents with Neurofibromatosis Type 1 (NF1): The Impact of Symptom Visibility and Bullying Behavior.

Neurofibromatosis type 1 (NF1) is an autosomal dominant condition, associated with neurocutaneous manifestations and neuropsychiatric manifestations. The present study explored the prevalence of bullying/cyberbullying behaviors and victimization behaviors in a cohort of children and adolescents with NF1. Possible gender differences and predictors of psychological symptoms, quality of life (QoL), and self-esteem were also examined. Thirty-eight school-aged participants with NF1 completed a psychological evaluation designed to assess anxiety and depression symptomatology, QoL, self-esteem, and the prevalence and extent of bullying/cyberbullying and victimization behaviors. We found that our participants frequently reported victimization behaviors rather than bullying/cyberbullying ones. Moreover, participants complained of depressive and anxiety symptomatology together with reduced self-esteem, and low psychosocial quality of life, with females reporting more severe performances than males. Furthermore, we found that reduced self-esteem was associated with more visibility of the NF1 symptoms, and victimization behaviors were found to mediate the relationship between anxiety and psychosocial QoL. Our findings indicated the presence of a maladaptive loop in children and adolescents with NF1 patients characterized by psychological symptoms, unfavorable self-perception, low self-esteem, and psychosocial difficulties that might be worsened by experiencing victimization behaviors. These results suggest the need to use a multidisciplinary approach in the diagnosis and treatment of NF1.

Incidence of cancer and related deaths in hemoglobinopathies: A follow-up of 4631 patients between 1970 and 2021.

BACKGROUND: The correlation between thalassemia and malignancies other than hepatocellular carcinoma (HCC) and the possible relationship between other hemoglobinopathies and tumor risk have been poorly evaluated. METHODS: Eight Italian specialized centers evaluated the incidence of malignant neoplasms in hemoglobinopathies as well as their sites and features. The study cohort included 4631 patients followed between 1970 and 2021 (transfusion-dependent ß-thalassemia, 55.6%; non-transfusion-dependent thalassemia, 17.7%; sickle cell disease, 17.6%; hemoglobin H disease, 8.3%). RESULTS: A total of 197 diagnoses of cancer were reported (incidence rate, 442 cases per 100,000 person-years). The liver was the most frequent site of tumors in both sexes, with a higher incidence (190 cases per 100,000 person-years) in comparison with the general population found in all types of hemoglobinopathies (except hemoglobin H disease). In recent years, tumors have become the second cause of death in patients with transfusion-dependent thalassemia. A lower risk of breast and prostate cancer was observed in the whole group of patients with hemoglobinopathies. The first cancer diagnoses dated back to the 1980s, and the incidence rate sharply increased after the 2000s. However, although the incidence rate of cancers of all sites but the liver continued to show an increasing trend, the incidence of HCC showed stability. CONCLUSIONS: These findings provide novel insights into the relationship between cancer and hemoglobinopathies and suggest that the overall risk is not increased in these patients. HCC has been confirmed as the most frequent tumor, but advances in chelation and the drugs that have led to the eradication of hepatitis C may explain the recent steadiness in the number of diagnoses that is reported here.

Molecular and Physiological Effects of Browning Agents on White Adipocytes from Bone Marrow Mesenchymal Stromal Cells.

Two different types of adipose depots can be observed in mammals: white adipose tissue (WAT) and brown adipose tissue (BAT). The primary role of WAT is to deposit surplus energy in the form of triglycerides, along with many metabolic and hormonal activities; as thermogenic tissue, BAT has the distinct characteristic of using energy and glucose consumption as a strategy to maintain the core body temperature. Under specific stimuli-such as exercise, cold exposure, and drug treatment-white adipocytes can utilize their extraordinary flexibility to transdifferentiate into brown-like cells, called beige adipocytes, thereby acquiring new morphological and physiological characteristics. For this reason, the process is identified as the 'browning of WAT'. We evaluated the ability of some drugs, including GW501516, sildenafil, and rosiglitazone, to induce the browning process of adult white adipocytes obtained from differentiated mesenchymal stromal cells (MSCs). In addition, we broadened our investigation by evaluating the potential browning capacity of IRISIN, a myokine that is stimulated by muscular exercises. Our data indicate that IRISIN was effective in promoting the browning of white adipocytes, which acquire increased expression of UCP1, increased mitochondrial mass, and modification in metabolism, as suggested by an increase of mitochondrial oxygen consumption, primarily in presence of glucose as a nutrient. These promising browning agents represent an appealing focus in the therapeutic approaches to counteracting metabolic diseases and their associated obesity.

Phase 2 study for nonmetastatic extremity high-grade osteosarcoma in pediatric and adolescent and young adult patients with a risk-adapted strategy based on ABCB1/P-glycoprotein expression: An Italian Sarcoma Group trial (ISG/OS-2).

BACKGROUND: According to retrospective osteosarcoma series, ABCB1/P-glycoprotein (Pgp) overexpression predicts for poor outcomes. A prospective trial to assess a risk-adapted treatment strategy using mifamurtide in Pgp+ patients was performed. METHODS: This was a phase 2, multicenter, uncontrolled trial including patients 40 years old or younger with nonmetastatic extremity high-grade osteosarcoma stratified according to Pgp expression. All patients received high-dose methotrexate, doxorubicin, and cisplatin (MAP) preoperatively. In Pgp+ patients, mifamurtide was added postoperatively and combined with MAP for a good histologic response (necrosis ≥ 90%; good responders [GRs]) or with high-dose ifosfamide (HDIFO) at 3 g/m2 /d on days 1 to 5 for a histologic response < 90% (poor responders [PRs]). Pgp- patients received MAP postoperatively. After an amendment, the cumulative dose of methotrexate was increased from 60 to 120 g/m2 (from 5 to 10 courses). The primary end point was event-free survival (EFS). A postamendment analysis was performed. RESULTS: In all, 279 patients were recruited, and 194 were included in the postamendment analysis: 70 (36%) were Pgp-, and 124 (64%) were Pgp+. The median follow-up was 51 months. For Pgp+ patients, 5-year EFS after definitive surgery (null hypothesis, 40%) was 69.8% (90% confidence interval [CI], 62.2%-76.2%): 59.8% in PRs and 83.7% in GRs. For Pgp- patients, the 5-year EFS rate was 66.4% (90% CI, 55.6%-75.1%). CONCLUSIONS: This study showed that adjuvant mifamurtide, combined with HDIFO for a poor response to induction chemotherapy, could improve EFS in Pgp+ patients. Overall, the outcomes compared favorably with previous series. Mifamurtide and HDIFO as salvage chemotherapy are worth further study.

Eltrombopag in paediatric immune thrombocytopenia: Iron metabolism modulation in mesenchymal stromal cells.

Immune thrombocytopenia (ITP) is an autoimmune disease caused by platelet destruction mediated by auto-antibody production. It is characterized by a compromised immune system and alteration of the inflammatory response. Mesenchymal stromal cells (MSCs) play an important role in modulating immune and inflammatory processes, exerting immune-suppressing and anti-inflammatory properties. In ITP-MSCs the activity and survival are strongly impaired. Eltrombopag (ELT) is a thrombopoietin receptor agonist approved in chronic ITP for stimulating platelet production. It has immunomodulating properties by stimulating T and B regulatory cell activity and by promoting a macrophage switch from the pro-inflammatory to the anti-inflammatory phenotype. ELT also exhibits iron-chelating properties. Iron is a crucial element involved in several physiologic processes, but its intracellular accumulation determines cell damages. Therefore, for the first time we analysed the effect of ELT on ITP-MSCs demonstrating its ability to restore survival and activity of MSCs directly and to promote their survival and proliferation indirectly, by iron metabolism modulation.

Intermittent macrothrombocytopenia in a novel patient with Takenouchi-Kosaki syndrome and review of literature.

Takenouchi-Kosaki syndrome (TKS) is a recently delineated syndromic form of thrombocytopenia strictly related to an hot-spot missense variant, p.Tyr64Cys, in CDC42 (Cell Division Control protein 42). Herein we report an additional patient with the p.Tyr64Cys aminoacidic substitution who showed the well-defined phenotypical TKS features and an intermittent, very mild, macrothrombocytopenia at 10.7 years of age (93,000/mL), that was only retrospectively valorized. Outside of this value the PLT count had always been higher than 100,000/mL. We also review literature data from patients carrying this recurrent variant. Our female patient presented with prenatal onset of short stature and microcephaly, camptodactyly, heart defects, typical facial gestalt, developmental delay, and not specific brain abnormalities. After several genetic investigations (karyotype, CGH-Array, targeted NGS analysis for short stature genes), by whole exome sequencing we identified the p.Tyr64Cys in CDC42, occurring de novo. The case presented here provides further evidence that macrothrombocytopenia can be intermittent and thus it might escape attention of clinicians. Without this key feature, TKS clinical presentation can overlap other syndromic forms of short stature. Immunodeficiency, autoimmunity, and malignancies were recently reported in patients with the p.Tyr64Cys substitution, making imperative an early diagnosis of Takenouchi-Kosaki syndrome to organize the most proper follow-up of these pediatric patients. The whole exome sequencing can be a solving tool in the challenge to the rare diseases.

Magnetic resonance features and cranial nerve involvement in pediatric head and neck rhabdomyosarcomas.

PURPOSE: Rhabdomyosarcoma (RMS) is a malignant tumor frequent in children. The frequency and characteristics of cranial nerve involvement in pediatric head and neck (H&N) RMS have been scarcely reported. The aim of this study is to review a large cohort of pediatric head and neck RMS with an emphasis on cranial nerve involvement. METHODS: We retrospectively reviewed H&N RMS cases from 3 tertiary hospitals over a 10-year period. Cranial nerve involvement was defined as radiologically apparent tumor extension along a nerve and/or the presence of secondary signs. Scans were reviewed by two pediatric neuroradiologists, blinded to clinical data. RESULTS: A total of 52 patients met the inclusion criteria. Histologically, 39/52 were embryonal RMS, while 13/52 were alveolar RMS. Regional lymph nodes metastases were present in 19.2%. Cranial nerve involvement was present in 36.5%. Nerves were mainly involved as a direct extension of the mass through skull base foramina or after invasion of cavernous sinus, Meckel's cave, orbital apex, or stylomastoid foramen. CONCLUSION: Cranial nerve involvement is frequent in pediatric head and neck RMS and occurs secondary to "geographic" invasion due to direct extension through skull base foramina or cavernous sinus. These tumors never showed distant perineural metastatic disease as is seen in cases of adult head and neck carcinomas. This implies a different biological interaction between the nerves and these tumors in comparison to adult H&N tumors.

A novel MEIS2 mutation explains the complex phenotype in a boy with a typical NF1 microdeletion syndrome.

Concurrence of distinct genetic conditions in the same patient is not rare. Several cases involving neurofibromatosis type 1 (NF1) have recently been reported, indicating the need for more extensive molecular analysis when phenotypic features cannot be explained by a single gene mutation. Here, we describe the clinical presentation of a boy with a typical NF1 microdeletion syndrome complicated by cleft palate and other dysmorphic features, hypoplasia of corpus callosum, and partial bicoronal craniosynostosis caused by a novel 2bp deletion in exon 2 of Meis homeobox 2 gene (MEIS2) inherited from the mildly affected father. This is only the second case of an inherited MEIS2 intragenic mutation reported to date. MEIS2 is known to be associated with cleft palate, intellectual disability, heart defects, and dysmorphic features. Our clinical report suggests that this gene may also have a role in cranial morphogenesis in humans, as previously observed in animal models.

Evaluation of Browning Agents on the White Adipogenesis of Bone Marrow Mesenchymal Stromal Cells: A Contribution to Fighting Obesity.

Brown-like adipocytes can be induced in white fat depots by a different environmental or drug stimuli, known as "browning" or "beiging". These brite adipocytes express thermogenin UCP1 protein and show different metabolic advantages, such as the ability to acquire a thermogenic phenotype corresponding to standard brown adipocytes that counteracts obesity. In this research, we evaluated the effects of several browning agents during white adipocyte differentiation of bone marrow-derived mesenchymal stromal cells (MSCs). Our in vitro findings identified two compounds that may warrant further in vivo investigation as possible anti-obesity drugs. We found that rosiglitazone and sildenafil are the most promising drug candidates for a browning treatment of obesity. These drugs are already available on the market for treating diabetes and erectile dysfunction, respectively. Thus, their off-label use may be contemplated, but it must be emphasized that some severe side effects are associated with use of these drugs.