Occurrence of high-grade glioma in Noonan syndrome: Report of two cases

A rare association of a high grade glioblastoma, cerebral abscess and acute lymphoblastic leukemia in a child with Noonan syndrome

Noonan syndrome is a genetic disorder frequently caused by PTPN11 mutations. Patients with Noonan syndrome are characterized by facial dysmorphism, short stature and congenital heart defects and they have a reported predisposition to malignancies such as leukemia, and solid and central nervous system tumors. Here, we report a case of a 14-year-old boy with Noonan syndrome treated for T-cell acute lymphoblastic leukemia who presented with 2 concomitant abnormalities: cerebral abscess and high grade glioblastoma. This exceptional association exhibits to a poorer prognosis and may sometimes delay the diagnosis and therefore the therapeutic intervention.

ALK Amplification and Rearrangements Are Recurrent Targetable Events in Congenital and Adult Glioblastoma

PURPOSE

Anaplastic lymphoma kinase (ALK) aberrations have been identified in pediatric-type infant gliomas, but their occurrence across age groups, functional effects, and treatment response has not been broadly established.

EXPERIMENTAL DESIGN

We performed a comprehensive analysis of ALK expression and genomic aberrations in both newly generated and retrospective data from 371 glioblastomas (156 adult, 205 infant/pediatric, and 10 congenital) with in vitro and in vivo validation of aberrations.

RESULTS

ALK aberrations at the protein or genomic level were detected in 12% of gliomas (45/371) in a wide age range (0-80 years). Recurrent as well as novel ALK fusions (LRRFIP1-ALK, DCTN1-ALK, PRKD3-ALK) were present in 50% (5/10) of congenital/infant, 1.4% (3/205) of pediatric, and 1.9% (3/156) of adult GBMs. ALK fusions were present as the only candidate driver in congenital/infant GBMs and were sometimes focally amplified. In contrast, adult ALK fusions co-occurred with other oncogenic drivers. No activating ALK mutations were identified in any age group. Novel and recurrent ALK rearrangements promoted STAT3 and ERK1/2 pathways and transformation in vitro and in vivo. ALK-fused GBM cellular and mouse models were responsive to ALK inhibitors, including in patient cells derived from a congenital GBM. Relevant to the treatment of infant gliomas, we showed that ALK protein appears minimally expressed in the forebrain at perinatal stages, and no gross effects on perinatal brain development were seen in pregnant mice treated with the ALK inhibitor ceritinib.

CONCLUSIONS

These findings support use of brain-penetrant ALK inhibitors in clinical trials across infant, pediatric, and adult GBMs. See related commentary by Mack and Bertrand, p. 2567.

Neurosurgical aspects of Noonan syndrome

PURPOSE

Noonan syndrome (NS) is a rare neurodevelopmental syndrome characterized by dysmorphic features, congenital heart defects, neurodevelopmental delay, and bleeding diathesis. Though rare, several neurosurgical manifestations have been associated with NS, such as Chiari malformation (CM-I), syringomyelia, brain tumors, moyamoya, and craniosynostosis. We describe our experience in treating children with NS and various neurosurgical conditions, and review the current literature on neurosurgical aspects of NS.

METHODS

Data were retrospectively collected from the medical records of children with NS who were operated at a tertiary pediatric neurosurgery department, between 2014 and 2021. Inclusion criteria were clinical or genetic diagnosis of NS, age < 18 years at treatment, and need for a neurosurgical intervention of any kind.

RESULTS

Five cases fulfilled the inclusion criteria. Two had tumors, one underwent surgical resection. Three had CM-I, syringomyelia, and hydrocephalus, of whom one also had craniosynostosis. Comorbidities included pulmonary stenosis in two patients and hypertrophic cardiomyopathy in one. Three patients had bleeding diathesis, two of them with abnormal coagulation tests. Four patients were treated preoperatively with tranexamic acid, and two with Von Willebrand factor or platelets (1 each). One patient with a clinical bleeding predisposition developed hematomyelia following a syringe-subarachnoid shunt revision.

CONCLUSIONS

NS is associated with a spectrum of central nervous system abnormalities, some of which with known etiology, while in others a pathophysiological mechanism has been suggested in the literature. When operating on a child with NS, a meticulous anesthetic, hematologic, and cardiac evaluation should be conducted. Neurosurgical interventions should then be planned accordingly.

Cancer incidence and surveillance strategies in individuals with RASopathies

RASopathies are a set of clinical syndromes that have molecular and clinical overlap. Genetically, these syndromes are defined by germline pathogenic variants in RAS/MAPK pathway genes resulting in activation of this pathway. Clinically, their common molecular signature leads to comparable phenotypes, including cardiac anomalies, neurologic disorders and notably, elevated cancer risk. Cancer risk in individuals with RASopathies has been estimated from retrospective reviews and cohort studies. For example, in Costello syndrome, cancer incidence is significantly elevated over the general population, largely due to solid tumors. In some forms of Noonan syndrome, cancer risk is also elevated over the general population and is enriched for hematologic malignancies. Thus, cancer surveillance guidelines have been developed to monitor for the occurrence of such cancers in individuals with some RASopathies. These include abdominal ultrasound and urinalyses for individuals with Costello syndrome, while complete blood counts and splenic examination are recommended in Noonan syndrome. Improved cancer risk estimates and refinement of surveillance recommendations will improve the care of individuals with RASopathies.

Inside the Noonan "universe": Literature review on growth, GH/IGF axis and rhGH treatment: Facts and concerns

Noonan syndrome (NS) is a disorder characterized by a typical facial gestalt, congenital heart defects, variable cognitive deficits, skeletal defects, and short stature. NS is caused by germline pathogenic variants in genes coding proteins with a role in the RAS/mitogen-activated protein kinase signaling pathway, and it is typically associated with substantial genetic and clinical complexity and variability. Short stature is a cardinal feature in NS, with evidence indicating that growth hormone (GH) deficiency, partial GH insensitivity, and altered response to insulin-like growth factor I (IGF-1) are contributing events for growth failure in these patients. Decreased IGF-I, together with low/normal responses to GH pharmacological provocation tests, indicating a variable presence of GH deficiency/resistance, in particular in subjects with pathogenic PTPN11 variants, are frequently reported. Nonetheless, short- and long-term studies have demonstrated a consistent and significant increase in height velocity (HV) in NS children and adolescents treated with recombinant human GH (rhGH). While the overall experience with rhGH treatment in NS patients with short stature is reassuring, it is difficult to systematically compare published data due to heterogeneous protocols, potential enrolment bias, the small size of cohorts in many studies, different cohort selection criteria and varying durations of therapy. Furthermore, in most studies, the genetic information is lacking. NS is associated with a higher risk of benign and malignant proliferative disorders and hypertrophic cardiomyopathy, and rhGH treatment may further increase risk in these patients, especially as dosages vary widely. Herein we provide an updated review of aspects related to growth, altered function of the GH/IGF axis and cell response to GH/IGF stimulation, rhGH treatment and its possible adverse events. Given the clinical variability and genetic heterogeneity of NS, treatment with rhGH should be personalized and a conservative approach with judicious surveillance is recommended. Depending on the genotype, an individualized follow-up and close monitoring during rhGH treatments, also focusing on screening for neoplasms, should be considered.

Spinal cord glioblastoma multiforme in a patient with Noonan syndrome: A clinical report

INTRODUCTION

Currently, there are only 3 reported cases of central nervous system malignancies in patients with Noonan syndrome in the literature, all of which are intracranial pathologies. To our knowledge, there are no cases of spinal cord glioblastoma multiforme reported in the literature.

CASE DESCRIPTION

We describe the case of a 12-year-old girl with Noonan syndrome who presented with back pain and new onset neurological deficits and was found to have a spinal cord lesion. T10-L1 laminoplasty with safe maximal resection was done. Postoperative pathological analysis identified this lesion as a high-grade astrocytoma consistent with glioblastoma multiforme.

CONCLUSIONS

Spinal cord glioblastoma multiforme is a rare occurrence in the general population, particularly in a patient with an underlying diagnosis of Noonan syndrome. Patients with spinal cord tumors can present with a multitude of clinical signs and symptoms and treatment should not be delayed.

Recurrent ganglioneuroma in PTPN11-associated Noonan syndrome: A case report and literature review

Noonan syndrome (NS) is an autosomal dominant condition with variable expressivity most commonly due to a germline pathogenic variant in PTPN11, which encodes the protein tyrosine phosphatase SHP-2. Gain-of-function variants in PTPN11 are known to promote oncogenic behavior in affected tissues. We report the clinical description of a young adult male presenting with relapsing ganglioneuromas, dysmorphic features, cardiac abnormalities, and multiple lentigines, strongly suspicious for NS. Solid tumor testing identified the recurrent pathogenic c.922G>A (p.Asn308Asp) in PTPN11. Proband and parental blood sampling testing confirmed c.922G>A as a de novo germline alteration. Comprehensive literature review of solid tumors specifically associated to PTPN11, indicates that this is the first documentation of ganglioneuroma and its clinical recurrence after resection in conjunction with a genetically confirmed NS diagnosis. The findings in our patient further extend the list of neuroblastic and neural crest-derived neoplasms associated with this condition.

Effect of Growth Hormone Therapy in Patients with Noonan Syndrome: A Retrospective Study

BACKGROUND

Noonan syndrome is an autosomal dominant condition with an incidence of 1:1000 to 1:2500. The disorder is associated with distinct dysmorphic features, cardiac anomalies, developmental delay and delayed puberty. Short stature is a recognised feature of Noonan syndrome.

OBJECTIVES

The aim of this study is to assess the effect of growth hormone treatment in patients with Noonan syndrome.

METHODS

Retrospective data was collected from patients with Noonan syndrome treated with growth hormone. The results were analysed with variables expressed as mean values and standard deviation scores.

RESULTS

Twelve Noonan syndrome patients (M: F = 10:2) treated with growth hormone were identified. The mean age of starting growth hormone was 8 years, with baseline height standard deviation score of -2.96 (range: -1.64 to -5.54). The height standard deviation score significantly improved to -2.50 (P = 0.0035) and then -2.22 (P = 0.0025), following one and two years of treatment, respectively. The average height velocity for the patients prior to starting treatment was 5.16cm/year (range: 2.4 - 8.2 cm/year), which significantly improved to 7.76cm/year (ranging from 4.1 to 12.8 cm/year) after one year of growth hormone treatment (P = 0.020) and to 6.51cm/year at the end of two years.

CONCLUSIONS

Our study has shown that growth hormone treatment significantly improves the height standard deviation score of patients with Noonan syndrome over a two-year course of growth hormone therapy without any side effects. Further research is required to analyse the long-term effect of growth hormone therapy in patients with Noonan syndrome, including the impact on final adult height.

Low-Grade Gliomas in Patients with Noonan Syndrome: Case-Based Review of the Literature

Noonan syndrome (NS) is a congenital autosomic dominant condition characterized by a variable spectrum from a clinical and genetical point of view. Germline mutations in more than ten genes involved in RAS-MAPK signal pathway have been demonstrated to cause the disease. An higher risk for leukemia and solid malignancies, including brain tumors, is related to NS. A review of the published literature concerning low grade gliomas (LGGs) in NS is presented. We described also a 13-year-old girl with NS associated with a recurrent mutation in PTPN11, who developed three different types of brain tumors, i.e., an optic pathway glioma, a glioneuronal neoplasm of the left temporal lobe and a cerebellar pilocytic astrocytoma. Molecular characterization of the glioneuronal tumor allowed to detect high levels of phosphorylated MTOR (pMTOR); therefore, a therapeutic approach based on an mTOR inhibitor (everolimus) was elected. The treatment was well tolerated and proved to be effective, leading to a stabilization of the tumor, which was surgical removed. The positive outcome of the present case suggests considering this approach for patients with RASopathies and brain tumors with hyperactivated MTOR signaling.

SHP2 mutations induce precocious gliogenesis of Noonan syndrome-derived iPSCs during neural development in vitro

Background

Noonan syndrome (NS) is a developmental disorder caused by mutations of Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP2). Although NS patients have diverse neurological manifestations, the mechanisms underlying the involvement of SHP2 mutations in neurological dysfunction remain elusive.

Methods

Induced pluripotent stem cells generated from dermal fibroblasts of three NS-patients (NS-iPSCs) differentiated to the neural cells by using two different culture systems, 2D- and 3D-cultured systems in vitro.

Results

Here we represent that SHP2 mutations cause aberrant neural development. The NS-iPSCs exhibited impaired development of EBs in which BMP and TGF-β signalings were activated. Defective early neuroectodermal development of NS-iPSCs recovered by inhibition of both signalings and further differentiated into NPCs. Intriguingly, neural cells developed from NS-NPCs exhibited abundancy of the glial cells, neurites of neuronal cells, and low electrophysiological property. Those aberrant phenotypes were also detected in NS-cerebral organoids. SHP2 inhibition in the NS-NPCs and NS-cerebral organoids ameliorated those anomalies such as biased glial differentiation and low neural activity.

Conclusion

Our findings demonstrate that SHP2 mutations contribute to precocious gliogenesis in NS-iPSCs during neural development in vitro.

A First Case Report of Subependymoma in PTPN11 Mutation-Associated Noonan Syndrome

Noonan syndrome (NS) is an autosomal dominant disorder in some cases caused by PTPN11 mutations. Since somatic mutations in PTPN11 are seen in several tumor types, NS which causes germline PTPN11 mutations are also increase the risk of hematologic malignancies and brain solid tumors. However, the report of brain tumors in Noonan syndrome remains rather rare. Here, we report the first case of an 11-year-old Thai boy with Noonan syndrome who presented with symptoms related to hydrocephalus secondary to subependymoma in the fourth ventricle, and PTPN11 mutation was identified in this patient.