Recommendations for Cancer Surveillance in Individuals with RASopathies and Other Rare Genetic Conditions with Increased Cancer Risk

Screening and interventional strategies for the late effects and toxicities of hematological malignancy treatments in pediatric survivors

INTRODUCTION

Advancements in pediatric cancer treatment have increased patient survival rates; however, childhood cancer survivors may face long-term health challenges due to treatment-related effects on organs. Regular post-treatment surveillance and early intervention are crucial for improving the survivors' quality of life and long-term health outcomes. The present paper highlights the significance of late effects in childhood cancer survivors, particularly those with hematologic malignancies, stressing the importance of a vigilant follow-up approach to ensure better overall well-being.

AREAS COVERED

This article provides an overview of the treatment history of childhood leukemia and lymphoma as well as outlines the emerging late effects of treatments. We discuss the various types of these complications and their corresponding risk factors.

EXPERT OPINION

Standardizing survivorship care in pediatric cancer aims to improve patient well-being by optimizing their health outcomes and quality of life. This involves early identification and intervention of late effects, requiring collaboration among specialists, nurses, and advocates, and emphasizing data sharing and international cooperation.

Cancer predisposing syndromes in childhood and adolescence pose several challenges necessitating interdisciplinary care in dedicated programs

Introduction

Genetic disposition is a major etiologic factor in childhood cancer. More than 100 cancer predisposing syndromes (CPS) are known. Surveillance protocols seek to mitigate morbidity and mortality. To implement recommendations in patient care and to ascertain that the constant gain of knowledge forces its way into practice specific pediatric CPS programs were established.

Patients and methods

We retrospectively analyzed data on children, adolescents, and young adults referred to our pediatric CPS program between October 1, 2021, and March 31, 2023. Follow-up ended on December 31, 2023.

Results

We identified 67 patients (30 male, 36 female, 1 non-binary, median age 9.5 years). Thirty-five patients were referred for CPS surveillance, 32 for features suspicious of a CPS including café-au-lait macules (n = 10), overgrowth (n = 9), other specific symptoms (n = 4), cancer suspicious of a CPS (n = 6), and rare neoplasms (n = 3). CPS was confirmed by clinical criteria in 6 patients and genetic testing in 7 (of 13). In addition, 6 clinically unaffected at-risk relatives were identified carrying a cancer predisposing pathogenic variant. A total of 48 patients were eventually diagnosed with CPS, surveillance recommendations were on record for 45. Of those, 8 patients did not keep their appointments for various reasons. Surveillance revealed neoplasms (n = 2) and metachronous tumors (n = 4) by clinical (n = 2), radiological examination (n = 2), and endoscopy (n = 2). Psychosocial counselling was utilized by 16 (of 45; 35.6%) families.

Conclusions

The diverse pediatric CPSs pose several challenges necessitating interdisciplinary care in specified CPS programs. To ultimately improve outcome including psychosocial well-being joint clinical and research efforts are necessary.

Defining the variant-phenotype correlation in patients affected by Noonan syndrome with the RAF1:c.770C>T p.(Ser257Leu) variant

Hypertrophic cardiomyopathy (HCM) is the major contributor to morbidity and mortality in Noonan syndrome (NS). Gain-of-function variants in RAF1 are associated with high prevalence of HCM. Among these, NM_002880.4:c.770C > T, NP_002871.1:p.(Ser257Leu) accounts for approximately half of cases and has been reported as associated with a particularly severe outcome. Nevertheless, comprehensive studies on cases harboring this variant are missing. To precisely define the phenotype associated to the RAF1:c.770C > T, variant, an observational retrospective analysis on patients carrying the c.770C > T variant was conducted merging 17 unpublished patients and literature-derived ones. Data regarding prenatal findings, clinical features and cardiac phenotypes were collected to provide an exhaustive description of the associated phenotype. Clinical information was collected in 107 patients. Among them, 92% had HCM, mostly diagnosed within the first year of life. Thirty percent of patients were preterm and 47% of the newborns was admitted in a neonatal intensive care unit, mainly due to respiratory complications of HCM and/or pulmonary arterial hypertension. Mortality rate was 13%, mainly secondary to HCM-related complications (62%) at the average age of 7.5 months. Short stature had a prevalence of 91%, while seizures and ID of 6% and 12%, respectively. Two cases out of 75 (3%) developed neoplasms. In conclusion, patients with the RAF1:c.770C > T pathogenic variant show a particularly severe phenotype characterized by rapidly progressive neonatal HCM and high mortality rate suggesting the necessity of careful monitoring and early intervention to prevent or slow down the progression of HCM.

The Approach to a Child with Dysmorphic Features: What the Pediatrician Should Know

The advancement of genetic knowledge and the discovery of an increasing number of genetic disorders has made the role of the geneticist progressively more complex and fundamental. However, most genetic disorders present during childhood; thus, their early recognition is a challenge for the pediatrician, who will be also involved in the follow-up of these children, often establishing a close relationship with them and their families and becoming a referral figure. In this review, we aim to provide the pediatrician with a general knowledge of the approach to treating a child with a genetic syndrome associated with dysmorphic features. We will discuss the red flags, the most common manifestations, the analytic collection of the family and personal medical history, and the signs that should alert the pediatrician during the physical examination. We will offer an overview of the physical malformations most commonly associated with genetic defects and the way to describe dysmorphic facial features. We will provide hints about some tools that can support the pediatrician in clinical practice and that also represent a useful educational resource, either online or through apps downloaded on a smartphone. Eventually, we will offer an overview of genetic testing, the ethical considerations, the consequences of incidental findings, and the main indications and limitations of the principal technologies.

Expanding the Phenotypic and Genotypic Spectrum of Weaver Syndrome: A Missense Variant of the EZH2 Gene

Introduction

Weaver syndrome (WS) is a rare autosomal dominant disorder characterized by distinctive facial features, pre- and post-natal overgrowth, macrocephaly, and variable developmental delay. The characteristic facial features are ocular hypertelorism, a broad forehead, almond-shaped palpebral fissures and, in early childhood, large, fleshy ears, a pointed "stuck-on" chin with horizontal skin creases, and retrognathia. Heterozygous pathogenic/likely pathogenic variants in the enhancer of zeste homolog 2 (EZH2) gene are responsible for WS.

Case Presentation

Here, we report a male patient with a heterozygous likely pathogenic variant in EZH2 gene who has tall stature, distinctive facial features, mild development delay, hypoxic-ischemic encephalopathy with a MRI finding of periventricular leukomalacia, gingival hypertrophy, and early onset high hypermetropia.

Conclusion

This case demonstrates the importance of reporting detailed molecular and clinical findings in patients to expand the genotypic and phenotypic findings of this rare syndrome.

From Churchill to Elephants: The Role of Protective Genes against Cancer

Richard Peto's paradox, first described in 1975 from an epidemiological perspective, established an inverse correlation between the probability of developing cancer in multicellular organisms and the number of cells. Larger animals exhibit fewer tumors compared to smaller ones, though exceptions exist. Mice are more susceptible to cancer than humans, while elephants and whales demonstrate significantly lower cancer prevalence rates than humans. How nature and evolution have addressed the issue of cancer in the animal kingdom remains largely unexplored. In the field of medicine, much attention has been devoted to cancer-predisposing genes, as they offer avenues for intervention, including blocking, downregulating, early diagnosis, and targeted treatment. Predisposing genes also tend to manifest clinically earlier and more aggressively, making them easier to identify. However, despite significant strides in modern medicine, the role of protective genes lags behind. Identifying genes with a mild predisposing effect poses a significant challenge. Consequently, comprehending the protective function conferred by genes becomes even more elusive, and their very existence is subject to questioning. While the role of variable expressivity and penetrance defects of the same variant in a family is well-documented for many hereditary cancer syndromes, attempts to delineate the function of protective/modifier alleles have been restricted to a few instances. In this review, we endeavor to elucidate the role of protective genes observed in the animal kingdom, within certain genetic syndromes that appear to act as cancer-resistant/repressor alleles. Additionally, we explore the role of protective alleles in conditions predisposing to cancer. The ultimate goal is to discern why individuals, like Winston Churchill, managed to live up to 91 years of age, despite engaging in minimal physical activity, consuming large quantities of alcohol daily, and not abstaining from smoking.

Outcomes following major thoracoabdominal cancer resection in adults with congenital heart disease

BACKGROUND

While advances in medical and surgical management have allowed >97% of congenital heart disease (CHD) patients to reach adulthood, a growing number are presenting with non-cardiovascular malignancies. Indeed, adults with CHD are reported to face a 20% increase in cancer risk, relative to others, and cancer has become the fourth leading cause of death among this population. Surgical resection remains a mainstay in management of thoracoabdominal cancers. However, outcomes following cancer resection among these patients have not been well established. Thus, we sought to characterize clinical and financial outcomes following major cancer resections among adult CHD patients.

METHODS

The 2012-2020 National Inpatient Sample was queried for all adults (CHD or non-CHD) undergoing lobectomy, esophagectomy, gastrectomy, pancreatectomy, hepatectomy, or colectomy for cancer. To adjust for intergroup differences in baseline characteristics, entropy balancing was applied to generate balanced patient groups. Multivariable models were constructed to assess outcomes of interest.

RESULTS

Of 905,830 patients undergoing cancer resection, 1,480 (0.2%) had concomitant CHD. The overall prevalence of such patients increased from <0.1% in 2012 to 0.3% in 2012 (P for trend<0.001). Following risk adjustment, CHD was linked with greater in-hospital mortality (AOR 2.00, 95%CI 1.06-3.76), as well as a notable increase in odds of stroke (AOR 8.94, 95%CI 4.54-17.60), but no statistically significant difference in cardiac (AOR 1.33, 95%CI 0.69-2.59) or renal complications (AOR 1.35, 95%CI 0.92-1.97). Further, CHD was associated with a +2.39 day incremental increase in duration of hospitalization (95%CI +1.04-3.74) and a +$11,760 per-patient increase in hospitalization expenditures (95%CI +$4,160-19,360).

CONCLUSIONS

While a growing number of patients with CHD are undergoing cancer resection, they demonstrate inferior clinical and financial outcomes, relative to others. Novel screening, risk stratification, and perioperative management guidelines are needed for these patients to provide evidence-based recommendations for this complex and unique cohort.

Mastocytosis in a Case of Noonan Syndrome Caused by a De Novo Pathogenic CBL Variant

Noonan syndrome is an autosomal dominant disease characterized by multi-organ disorders caused by variants of genes involved in the RAS/MAPK signaling pathway. The nine causative genes including PTPN11 and CBL have been identified. Mastocytosis is a disease characterized by mast cell proliferation in skin, bone marrow, and other organs. To date, no previous cases of Noonan syndrome with mastocytosis caused by a pathogenic CBL variant have been reported. A boy was diagnosed with Noonan syndrome at 8 months of age with facial features and minor anomaly of his body. He presented with brown nodules of 5-10 mm on his body since the age of 2 months. The patient was diagnosed with mastocytosis by a biopsy specimen from brown nodules, which showed infiltration of mast cells. Whole-exome sequencing of the parent-patient trio revealed a de novo pathogenic CBL variant. The occurrence of mastocytosis may be a cue for the analysis of the CBL gene in Noonan syndrome. The CBL gene is involved in mastocytosis and various cancers. In the case of the pathogenic variant, long-term follow-up for the risk of cancers related to the CBL variant is necessary.

Role of SHP2 (PTPN11) in glycoprotein VI-dependent thrombus formation: Improved platelet responsiveness by the allosteric drug SHP099 in Noonan syndrome patients

INTRODUCTION

The protein tyrosine phosphatase SHP2 (PTPN11) is a negative regulator of glycoprotein VI (GPVI)-induced platelet signal under certain conditions. Clinical trials with derivatives of the allosteric drug SHP099, inhibiting SHP2, are ongoing as potential therapy for solid cancers. Gain-of-function mutations of the PTPN11 gene are observed in part of the patients with the Noonan syndrome, associated with a mild bleeding disorder. Assessment of the effects of SHP2 inhibition in platelets from controls and Noonan syndrome patients.

MATERIALS AND METHODS

Washed human platelets were incubated with SHP099 and stimulated with collagen-related peptide (CRP) for stirred aggregation and flow cytometric measurements. Whole-blood microfluidics assays using a dosed collagen and tissue factor coating were performed to assess shear-dependent thrombus and fibrin formation. Effects on clot formation were evaluated by thromboelastometry.

RESULTS

Pharmacological inhibition of SHP2 did not alter GPVI-dependent platelet aggregation under stirring, but it enhanced integrin αIIbβ3 activation in response to CRP. Using whole-blood microfluidics, SHP099 increased the thrombus buildup on collagen surfaces. In the presence of tissue factor and coagulation, SHP099 increased thrombus size and reduced time to fibrin formation. Blood from PTPN11-mutated Noonan syndrome patients, with low platelet responsiveness, after ex vivo treatment with SHP099 showed a normalized platelet function. In thromboelastometry, SHP2 inhibition tended to increase tissue factor-induced blood clotting profiles with tranexamic acid, preventing fibrinolysis.

CONCLUSION

Pharmacological inhibition of SHP2 by the allosteric drug SHP099 enhances GPVI-induced platelet activation under shear conditions with a potential to improve platelet functions of Noonan syndrome patients.

Abnormalities of pubertal development and gonadal function in Noonan syndrome

Background

Noonan syndrome (NS) is a genetic multisystem disorder characterised by variable clinical manifestations including dysmorphic facial features, short stature, congenital heart disease, renal anomalies, lymphatic malformations, chest deformities, cryptorchidism in males.

Methods

In this narrative review, we summarized the available data on puberty and gonadal function in NS subjects and the role of the RAS/mitogen-activated protein kinase (MAPK) signalling pathway in fertility. In addition, we have reported our personal experience on pubertal development and vertical transmission in NS.

Conclusions

According to the literature and to our experience, NS patients seem to have a delay in puberty onset compared to the physiological timing reported in healthy children. Males with NS seem to be at risk of gonadal dysfunction secondary not only to cryptorchidism but also to other underlying developmental factors including the MAP/MAPK pathway and genetics. Long-term data on a large cohort of males and females with NS are needed to better understand the impact of delayed puberty on adult height, metabolic profile and well-being. The role of genetic counselling and fertility related-issues is crucial.

Beyond the known phenotype of sotos syndrome: a 31-individuals cohort study

Introduction

Sotos Syndrome (SS, OMIM#117550) is a heterogeneous genetic condition, recognized by three main clinical features present in most cases: overgrowth with macrocephaly, typical facial appearance and different degrees of intellectual disability. Three different types are described caused by variants or deletions/duplications in NSD1, NFIX and APC2 genes. We aimed to describe a cohort of pediatric patients reporting the typical and unexpected findings in order to expand the phenotype of this syndrome and trying to find genotype-phenotype correlations.

Methods

In our referral center, we collected and analyzed clinical and genetic data of 31-patients cohort diagnosed with SS.

Results

All of them presented with overgrowth, typical dysmorphic features and different degree of developmental delay. Although structural cardiac defects have been reported in SS, non-structural diseases such as pericarditis were outstanding in our cohort. Moreover, we described here novel oncological malignancies not previously linked to SS such as splenic hamartoma, retinal melanocytoma and acute lymphocytic leukemia. Finally, five patients suffered from recurrent onychocryptosis that required surgical procedures, as an unreported prevalent medical condition.

Discussion

This is the first study focusing on multiple atypical symptoms in SS at the time that revisits the spectrum of clinical and molecular basis of this heterogeneous entity trying to unravel a genotype-phenotype correlation.

Cancer in Costello syndrome: a systematic review and meta-analysis

BACKGROUND

Costello syndrome (CS) is a cancer-predisposition disorder caused by germline pathogenic variants in HRAS. We conducted a systematic review using case reports and case series to characterise cancer risk in CS.

METHODS

We conducted a systematic review to identify CS cases to create a retrospective cohort. We tested genotype-phenotype correlations and calculated cumulative incidence and hazard rates (HR) for cancer and cancer-free death, standardised incidence rates (SIR) and survival after cancer.

RESULTS

This study includes 234 publications reporting 621 patients from 35 countries. Over nine percent had cancer, including rhabdomyosarcoma, bladder, and neuroblastoma. The rate of cancer and death associated with p.Gly12Ser were lower when compared to all other variants (P < 0.05). Higher mortality for p.Gly12Cys, p.Gly12Asp, p.Gly12Val and p.Gly60Val and higher malignancy rate for p.Gly12Ala were confirmed (P < 0.05). Cumulative incidence by age 20 was 13% (cancer) and 11% (cancer-free death). HR (death) was 3-4% until age 3. Statistically significant SIRs were found for rhabdomyosarcoma (SIR = 1240), bladder (SIR = 1971), and neuroblastoma (SIR = 60). Survival after cancer appeared reduced.

CONCLUSIONS

This is the largest investigation of cancer in CS to date. The high incidence and SIR values found to highlight the need for rigorous surveillance and evidence-based guidelines for this high-risk population.

5q35 duplication syndrome: Narrowing the critical region on the distal side and further evidence of intrafamilial variability and expression

The key features of patients with a microduplication 5q35.2q35.3 (including the NSD1 gene) are short stature, microcephaly, mild developmental delay, behavioral problems, digital anomalies and congenital anomalies of internal organs. This core phenotype can be viewed as the reversed phenotype of Sotos syndrome, which is caused by a microdeletion in the same chromosomal region or a pathogenic variant in the NSD1 gene, and includes tall stature and macrocephaly, developmental delay, and epilepsy. Here, we report on a patient and his mother, both with a 5q35.2q35.3 duplication, adding a fifth family to the recently published overview of 39 patients of Quintero-Rivera et al. Our patient had several congenital anomalies, intrauterine growth restriction with a persisting short stature, while his mother was only mildly affected with decreased growth parameters. In addition, he had hemophagogocytic lymphohistiocytosis (HLH) triggered by Haemophilus influenzae and was recently diagnosed with Ewing sarcoma. Our cases carry the smallest duplication published (ca 332 kb, arr[hg19] 5q35.2q35.3(176493106-176824785)x3) further narrowing the distal side of the critical region of the 5q35.2q35.3 duplication. Besides broadening the clinical phenotypic spectrum, our report indicates that the 5q35.2q35.3 microduplication also shows a large intra-familial variability and expression.

Exploring the values, preferences, and information needs of patients with NKX2-1-related disorders: A qualitative study protocol

BACKGROUND

NKX2-1-related disorders have a prevalence of 1:500,000 and are therefore considered a rare condition according to the European Commission's definition. The European Reference Network of Rare Neurological Disorders is developing the first clinical practice guideline on the management of this condition, with the support of the Andalusian Health Technology Assessment Area, Endo-ERN, ERN-Lung and Imegen, within the framework of the ERNs Guidelines programme (DG SANTE/2018/B3/030). Within the scope of this programme, it becomes necessary to explore the patient perspective in order to include it in the ongoing clinical practice guideline and accompanying patient information booklet.

METHODS AND ANALYSIS

This study will use qualitative methods to explore the values, preferences and information needs of patient with NKX2-1-related disorders and their caregivers. Participants will come from a variety of countries throughout Europe. One focus group and four semi-structured interviews will be conducted. Pairs will analyse the data using Grounded Theory. The Andalusian Regional Ministry of Health's Ethics Coordinating Committee for Biomedical Research (Sevilla, Andalucía, Spain) has approved this study protocol (29/03/2022).

DISCUSSION

This is the first study to explore the values, preferences, and information needs of patients with NKX2-1-related disorders. The proposed study's findings will contribute to the generation of useful knowledge that will provide guidance to improve the care given to patients with the studied condition. While this study will provide valuable insights into the perspectives of patients with NKX2-1-related disorders, the findings are unlikely to be generalizable to patients with other conditions.

Genetic predisposition to cancers in children and adolescents

PURPOSE OF REVIEW

Childhood cancer is rare, but it remains the leading cause of disease-related mortality among children 1-14 years of age. As exposure to environmental factors is lower in children, inherited genetic factors become an important player in the cause of childhood cancer. This review highlights the current knowledge and approach for cancer predisposition syndromes in children.

RECENT FINDINGS

Current literature suggests that 10-18% of paediatric cancer patients have an underlying genetic susceptibility to their disease. With better knowledge and technology, more genes and syndromes are being discovered, allowing tailored treatment and surveillance for the probands and their families.Studies have demonstrated that focused surveillance can detect early malignancies and increase overall survival in several cancer predisposition syndromes. Various approaches have been proposed to refine early tumour detection strategies while minimizing the burden on patients and families. Newer therapeutic strategies are being investigated to treat, or even prevent, tumours in children with cancer predisposition.

SUMMARY

This review summarizes the current knowledge about different cancer predisposition syndromes, focusing on the diagnosis, genetic counselling, surveillance and future directions.

Clinical and genetic features of luscan-lumish syndrome associated with a novel de novo variant of SETD2 gene: Case report and literature review

Introduction: Luscan-Lumish syndrome (LLS) is currently recognized as a rarely-observed condition featured with overgrowth, macrocephaly, obesity, type I Chiari malformation, and linguistic retardation. So far, there have been only a few LLS cases registered worldwide, but with none of them reported from China. To acquire a deeper understanding on the clinical and genetic features of this disease, a Chinese boy with LLS caused by a heterozygous variant in SETD2 gene was investigated in the present study. Methods: The patient was clinically examined and the medical history of his family was collected. Genetic testing was performed to determine the genetic etiology. Results: The proband was a boy aged 5-year-7-month-old, who was referred to our hospital due to "being a slow learner in kindergarten". The child had a history of delayed motor and language development in comparison to his peers. After admission, physical examination revealed tall stature and macrocephaly as the major manifestation, in addition to a relatively lower rating in intelligence assessment as well as abnormal MRI images showing a slightly shorter corpus callosum accompanied by a mildly thinner corpus callosum body. Whole exome sequencing (WES) revealed a heterozygous c.2514_2516delTAG (p.Ser838del) variant in SETD2 gene, which was subsequently identified as a novel de novo variant. According to the standardized genetic variant classification published by the American College of Medical Genetics and Genomics (ACMG), the variant, with a pathogenicity analysis result indicating PS2 + PM2_Supporting + PM4, was determined to be likely pathogenic. Through literature review, the clinical phenotypes of the 15 LLS cases were summarized, including 8 cases of overgrowth (53%), 13 cases of macrocephaly (87%), 11 cases of developmental delay (73%), 8 cases of autism (53%), and 7 cases of special facial features (47%). Besides, abnormal craniocerebral MRI findings were noticed in 7 cases. Despite that the mutation sites of the 15 patients varied from case to case, they showed a uniformly distributed pattern throughout the whole SETD2 gene, including 5 missense mutations, 5 frameshift mutations and 5 non-sense mutations. Conclusion: LLS, not having been recognized till recent years, is identified as an autosomal dominant syndrome triggered by SETD2 gene mutation. As the first report of LLS in China, the case in our study was proved to be associated with a unique type of SETD2 gene mutation that has never been reported previously, which is believed to enrich the mutation spectrum of SETD2 gene and also, deepening the clinicians' understanding on the disease.

Clinical overview on RASopathies

RASopathies comprise a group of clinically overlapping developmental disorders caused by genetic variations affecting components or modulators of the RAS-MAPK signaling cascade, which lead to dysregulation of signal flow through this pathway. Noonan syndrome and the less frequent, clinically related disorders, Costello syndrome, cardiofaciocutaneous syndrome, Noonan syndrome with multiple lentigines, and Noonan syndrome-like disorder with loose anagen hair are part of the RASopathy spectrum and share a recognizable pattern of multisystem involvement. This review describes the "Noonan syndrome-like" phenotype as a common phenotypic signature of generalized developmental RAS pathway dysregulation. Distinctive features of the different entities are revisited against the background of the understanding of underlying genetic alterations and genotype correlations, which has evolved rapidly during the past 20 years, thereby leading to suggestions regarding the nosology of RASopathies.

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.

Near-Haploid B-Cell Acute Lymphoblastic Leukemia in a Patient with Rubinstein-Taybi Syndrome

Rubinstein-Taybi syndrome (RSTS) is a rare disorder characterized by developmental delay, short stature, dysmorphic facies and skeletal abnormalities. RSTS has been linked to a variety of malignant and benign tumors, but the frequency and characteristics of RSTS-related neoplasms remain unclear. We describe a unique case of near haploid B-cell lymphoblastic leukemia (B-ALL) in a 6-year-old girl with RSTS who harbors a likely pathogenic variant in CREBBP. Somatic CREBBP variants are enriched in some subsets of ALL; however, germline variants have not been previously described in childhood leukemia and may represent an underrecognized predisposition to malignancy. Our patient's disease responded poorly to conventional chemotherapy and relapsed following a complete remission achieved with CD19 CAR T cell therapy. We propose that the constitutional CREBBP variant may have played a significant role in the leukemia's resistance to chemotherapy and this patient's poor response to therapy.

RASopathy Cohort of Patients Enrolled in a Brazilian Reference Center for Rare Diseases: A Novel Familial LZTR1 Variant and Recurrent Mutations

Purpose

Noonan syndrome and related disorders are genetic conditions affecting 1:1000-2000 individuals. Variants causing hyperactivation of the RAS/MAPK pathway lead to phenotypic overlap between syndromes, in addition to an increased risk of pediatric tumors. DNA sequencing methods have been optimized to provide a molecular diagnosis for clinical and genetic heterogeneity conditions. This work aimed to investigate the genetic basis in RASopathy patients through Next Generation Sequencing in a Reference Center for Rare Diseases (IFF/Fiocruz) and implement the precision medicine at a public health institute in Brazil.

Patients and Methods

This study comprises 26 cases with clinical suspicion of RASopathies. Sanger sequencing was used to screen variants in exons usually affected in the PTPN11 and HRAS genes for cases with clinical features of Noonan and Costello syndrome, respectively. Posteriorly, negative and new cases with clinical suspicion of RASopathy were analyzed by clinical or whole-exome sequencing.

Results

Molecular analysis revealed recurrent variants and a novel LZTR1 missense variant: 24 unrelated individuals with pathogenic variants [PTPN11(11), NF1(2), SOS1(2), SHOC2(2), HRAS(1), BRAF(1), LZTR (1), RAF1(1), KRAS(1), RIT1(1), a patient with co-occurrence of PTPN11 and NF1 mutations (1)]; familial cases carrying a known pathogenic variant in PTPN11 (mother-two children), and a previously undescribed paternally inherited variant in LZTR1. The comparative modeling analysis of the novel LZTR1 variant p.Pro225Leu showed local and global changes in the secondary and tertiary structures, showing a decrease of about 1% in the β-sheet content. Furthermore, evolutionary conservation indicated that Pro225 is in a highly conserved region, as observed for known dominant pathogenic variants in this protein.

Conclusion

Bringing precision medicine through NGS towards congenital syndromes promotes a better understanding of complex clinical and/or undiagnosed cases. The National Policy for Rare Diseases in Brazil emphasizes the importance of incorporating and optimizing diagnostic methodologies in the Unified Brazilian Health System (SUS). Therefore, this work is an important step for the NGS inclusion in diagnostic genetic routine in the public health system.

Diagnostic Strategies and Algorithms for Investigating Cancer Predisposition Syndromes in Children Presenting with Malignancy

Simple Summary

Here we provide an overview of several genetically determined conditions that predispose to the development of solid and hematologic malignancies in children. Diagnosing these conditions, whose prevalence is estimated around 10% in children with cancer, is useful to warrant personalized oncologic treatment and follow-up, as well as psychological and genetic counseling to these children and their families. We reviewed the most recent studies focusing on the prevalence of cancer predisposition syndromes in cancer-bearing children and the most-used clinical screening tools. Our work highlighted the value of clinical screening tools in the management of young cancer patients, especially in settings where genetic testing is not promptly accessible.

Abstract

In the past recent years, the expanding use of next-generation sequencing has led to the discovery of new cancer predisposition syndromes (CPSs), which are now known to be responsible for up to 10% of childhood cancers. As knowledge in the field is in constant evolution, except for a few “classic” CPSs, there is no consensus about when and how to perform germline genetic diagnostic studies in cancer-bearing children. Several clinical screening tools have been proposed to help identify the patients who carry higher risk, with heterogeneous strategies and results. After introducing the main clinical and molecular features of several CPSs predisposing to solid and hematological malignancies, we compare the available clinical evidence on CPS prevalence in pediatric cancer patients and on the most used decision-support tools in identifying the patients who could benefit from genetic counseling and/or direct genetic testing. This analysis highlighted that a personalized stepwise approach employing clinical screening tools followed by sequencing in high-risk patients might be a reasonable and cost-effective strategy in the care of children with cancer.

Genetic Disorders with Predisposition to Paediatric Haematopoietic Malignancies—A Review

The view of paediatric cancer as a genetic disease arises as genetic research develops. Germline mutations in cancer predisposition genes have been identified in about 10% of children. Paediatric cancers are characterized by heterogeneity in the types of genetic alterations that drive tumourigenesis. Interactions between germline and somatic mutations are a key determinant of cancer development. In 40% of patients, the family history does not predict the presence of inherited cancer predisposition syndromes and many cases go undetected. Paediatricians should be aware of specific symptoms, which highlight the need of evaluation for cancer syndromes. The quickest possible identification of such syndromes is of key importance, due to the possibility of early detection of neoplasms, followed by presymptomatic genetic testing of relatives, implementation of appropriate clinical procedures (e.g., avoiding radiotherapy), prophylactic surgical resection of organs at risk, or searching for donors of hematopoietic stem cells. Targetable driver mutations and corresponding signalling pathways provide a novel precision medicine strategy.Therefore, there is a need for multi-disciplinary cooperation between a paediatrician, an oncologist, a geneticist, and a psychologist during the surveillance of families with an increased cancer risk. This review aimed to emphasize the role of cancer-predisposition gene diagnostics in the genetic surveillance and medical care in paediatric oncology.

A deep phenotyping experience: up to date in management and diagnosis of Malan syndrome in a single center surveillance report

Background

Malan syndrome (MALNS) is a recently described ultrarare syndrome lacking guidelines for diagnosis, management and monitoring of evolutive complications. Less than 90 patients are reported in the literature and limited clinical information are available to assure a proper health surveillance.

Results

A multidisciplinary team with high expertise in MALNS has been launched at the “Ospedale Pediatrico Bambino Gesù”, Rome, Italy. Sixteen Italian MALNS individuals with molecular confirmed clinical diagnosis of MALNS were enrolled in the program. For all patients, 1-year surveillance in a dedicated outpatient Clinic was attained. The expert panel group enrolled 16 patients and performed a deep phenotyping analysis directed to clinically profiling the disorder and performing critical revision of previously reported individuals. Some evolutive complications were also assessed. Previously unappreciated features (e.g., high risk of bone fractures in childhood, neurological/neurovegetative symptoms, noise sensitivity and Chiari malformation type 1) requiring active surveillance were identified. A second case of neoplasm was recorded. No major cardiovascular anomalies were noticed. An accurate clinical description of 9 new MALNS cases was provided.

Conclusions

Deep phenotyping has provided a more accurate characterization of the main clinical features of MALNS and allows broadening the spectrum of disease. A minimal dataset of clinical evaluations and follow-up timeline has been proposed for proper management of patients affected by this ultrarare disorder.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13023-022-02384-9.

Neurofibromatosis type 1: A comparison of the 1997 NIH and the 2021 revised diagnostic criteria in 75 children and adolescents

PURPOSE

Examining a cohort of patients suspicious of neurofibromatosis type 1 (NF1) we compared the revised diagnostic criteria with the previous National Institutes of Health (NIH) diagnostic criteria. We asked whether the refinement improved distinguishing between NF1, Legius syndrome, and constitutional mismatch repair deficiency (CMMRD).

METHODS

A database search in the hospital information system of the University Children's Hospital Augsburg between 2017 and 2020 ascertained patients with International Classification of Diseases-10 code Q85.0; their clinical phenotype was evaluated by retrospective chart review.

RESULTS

A total of 75 patients were identified (median age 11.0 years [range 1.1-22.6 years]; 35 female). At first suspicion of NF1, 44 patients met the NIH criteria and 56 met the revised diagnostic criteria. In total, 12 patients were diagnosed with NF1 after performing molecular genetic testing. In 31 patients, only pigmentary findings were present, whereas nonpigmentary NF1 manifestations presented with time in 9 patients. In 1 patient a heterozygous variant of uncertain significance was identified in SPRED1. Requirements for CMMRD testing were fulfilled in another patient. A total of 3 patients presented with segmental clinical findings. Three additional patients did not meet the NIH criteria, 1 of them presented with 1 additional feature of CMMRD without fulfilling requirements for testing.

CONCLUSION

In our pediatric cohort, the revised diagnostic criteria discovered more patients with proven NF1 than the NIH criteria.

Growth, Endocrine Features, and Growth Hormone Treatment in Noonan Syndrome

Noonan syndrome is a heterogeneous congenital disorder. The main features are typical facial features, short stature and cardiac defects. The diagnosis is clinical: in 80% of patients with Noonan syndrome a genetic defect can be shown. Inheritance is predominantly autosomal dominant and seldom autosomal recessive. In 2001, PTPN11 was the first gene connected to Noonan syndrome, and until now, at least 20 other genes have been discovered. All genes code for proteins involved in the RAS-MAP-kinase pathway, and therefore, Noonan syndrome is one of the known RASopathies. Other RASopathies include neurofibromatosis and CFC syndrome. Short stature is one of the defining features of Noonan syndrome. The cause is not fully understood but is multifactorial. Other endocrinological features are confined to delayed puberty and hypogonadism in boys and males. To increase adult height, children with Noonan syndrome have been treated with human growth hormone since the 1990s. This seems to be beneficial in most of the children treated. In this narrative review, we describe the current knowledge on growth, endocrinological features and growth hormone treatment in patients with Noonan syndrome.

Cancer Predisposition Genes in Adolescents and Young Adults (AYAs): a Review Paper from the Italian AYA Working Group

PURPOSE OF REVIEW

The present narrative systematic review summarizes current knowledge on germline gene mutations predisposing to solid tumors in adolescents and young adults (AYAs).

RECENT FINDINGS

AYAs with cancer represent a particular group of patients with specific challenging characteristics and yet unmet needs. A significant percentage of AYA patients carry pathogenic or likely pathogenic variants (PV/LPVs) in cancer predisposition genes. Nevertheless, knowledge on spectrum, frequency, and clinical implications of germline variants in AYAs with solid tumors is limited. The identification of PV/LPV in AYA is especially critical given the need for appropriate communicative strategies, risk of second primary cancers, need for personalized long-term surveillance, potential reproductive implications, and cascade testing of at-risk family members. Moreover, these gene alterations may potentially provide novel biomarkers and therapeutic targets that are lacking in AYA patients. Among young adults with early-onset phenotypes of malignancies typically presenting at later ages, the increased prevalence of germline PV/LPVs supports a role for genetic counseling and testing irrespective of tumor type.

Pediatric solid tumors and associated cancer predisposition syndromes: Workup, management, and surveillance. A summary from the APSA Cancer Committee

BACKGROUND/PURPOSE

Cancer predisposition syndromes (CPS) are a heterogeneous group of inherited disorders that greatly increase the risk of developing malignancies. CPS are particularly relevant to pediatric surgeons since nearly 10% of cancer diagnoses are due to inherited genetic traits, and CPS often contribute to cancer development during childhood.

MATERIALS/METHODS

The English language literature was searched for manuscripts, practice guidelines, and society statements on "cancer predisposition syndromes in children". Following review of these manuscripts and cross-referencing of their bibliographies, tables were created to summarize findings of the most common CPS associated with surgically treated pediatric solid malignancies.

RESULTS

Pediatric surgeons should be aware of CPS as the identification of one of these syndromes can completely change the management of certain tumors, such as WT. The most common CPS associated with pediatric solid malignancies are outlined, with an emphasis on those most often encountered by pediatric surgeons: neuroblastoma, Wilms' tumor, hepatoblastoma, and medullary thyroid cancer. Frequently associated non-tumor manifestations of these CPS are also included as a guide to increase surgeon awareness. Screening and management guidelines are outlined, and published genetic testing and counseling guidelines are included where available.

CONCLUSION

Pediatric surgeons play an important role as surgical oncologists and are often the first point of contact for children with solid tumors. In their role of delivering a diagnosis and developing a follow-up and treatment plan as part of a multidisciplinary team, familiarity with common CPS will ensure evidence-based practices are followed, including important principles such as organ preservation and intensified surveillance plans. This review defines and summarizes the CPS associated with common childhood solid tumors encountered by the pediatric surgeon, as well as common non-cancerous disease stigmata that may help guide diagnosis.

TYPE OF STUDY

Summary paper.

LEVEL OF EVIDENCE

5.

Genodermatoses associated with melanocytic nevi

Though melanocytic nevi are ubiquitous in the general population, they can also be key cutaneous manifestations of genetic syndromes. We describe genodermatoses associated with melanocytic nevi and discuss their clinical characteristics, cutaneous manifestations, underlying genetics, and, if applicable, guidelines for when genetic testing should be performed. We categorized these genodermatoses based on their association with congenital nevi, acquired nevi, or nevi whose first appearance is unknown. In many cases, the distinctive morphology or distribution of melanocytic nevi can be an important clue that an underlying genetic syndrome is present, allowing both the patient as well as family members to be screened for the more serious complications of their genetic disorder and receive education on potential preventative measures. As we continue to advance our understanding of how various genotypes give rise to the wide spectrum of phenotypes observed in these genodermatoses, we shall be able to better stratify risk and tailor our screening methods to clinically manage the heterogeneous manifestations of genodermatoses among these patients.

Lymphatic Abnormalities in Noonan Syndrome Spectrum Disorders: A Systematic Review

Noonan syndrome spectrum disorders are a group of phenotypically related conditions, resembling Noonan syndrome, caused by germline pathogenic variants in genes within the Ras/mitogen-activated protein kinase (Ras/MAPK) signalling pathway. Lymphatic dysplasia with a clinical lymphatic abnormality is one of the major features. We performed a systematic review to get more insight in (1) the prevalence of clinically lymphatic abnormalities in patients with a genetically proven Noonan syndrome spectrum disorder, (2) if a genotype-lymphatic phenotype relation can be found and describe the clinical presentation and course of the lymphatic abnormality. Most studies report patients with Noonan syndrome. Prenatally, the prevalence of increased nuchal translucency differs from 7% in patients with pathogenic PTPN11 variants to 38% in patients with pathogenic RIT1 variants, and the prevalence of pleural effusions differed from 7% in patients with pathogenic SOS1 to 29% in patients with pathogenic RIT1 variants. Postnatally, the prevalence of lymphedema differs from 16% in patients with pathogenic PTPN11 variants to 44% in patients with pathogenic SOS1 variants, and the prevalence of acquired chylothorax is 4% in patients with pathogenic RIT1 variants. Lymphatic abnormalities do occur in patients with cardiofaciocutaneous syndrome and Costello syndrome. In conclusion, Noonan syndrome spectrum disorders, Noonan syndrome in particular, are associated with lymphatic abnormalities. Combining the available published literature about genetically proven Noonan syndrome spectrum disorders, it appears likely that the lifetime prevalence of these abnormalities in Noonan syndrome is higher than the 20% that were generally accepted so far. This is increasingly important, because the activation of the RAS/MAPK pathway can be inhibited by RAS/MAPK inhibitors, and clinically severe lymphatic abnormalities may improve.

The need for tumor surveillance of children and adolescents with cancer predisposition syndromes: a retrospective cohort study in a tertiary-care children's hospital

Expert recommendations for the management of tumor surveillance in children with a variety of cancer predisposition syndromes (CPS) are available. We aimed (1) at identifying and characterizing children who are affected by a CPS and (2) at comparing current practice and consensus recommendations of the American Association for Cancer Research workshop in 2016. We performed a database search in the hospital information system of the University Children's Hospital for CPS in children, adolescents, and young adults and complemented this by review of electronic patients' charts. Between January 1, 2017, and December 3, 2019, 272 patients with 41 different CPS entities were identified in 20 departments (144 [52.9%] male, 128 [47.1%] female, median age 9.1 years, range, 0.4-27.8). Three (1.1%) patients died of non-malignancy-associated complications of the CPS; 49 (18.0%) patients were diagnosed with malignancy and received regular follow-up. For 209 (95.0%) of the remaining 220 patients, surveillance recommendations were available: 30/220 (13.6%) patients received CPS consultations according to existing consensus recommendations, 22/220 (10.0%) institutional surveillance approaches were not complying with recommendations, 84/220 (38.2%) patients were seen for other reasons, and 84/220 (38.2%) were not routinely cared for. Adherence to recommendations differed extensively among CPS entities.

CONCLUSION

The spectrum of CPS patients at our tertiary-care children's hospital is manifold. For most patients, awareness of cancer risk has to be enhanced and current practice needs to be adapted to consensus recommendations. Offering specialized CPS consultations and establishing education programs for patients, relatives, and physicians may increase adherence to recommendations.

WHAT IS KNOWN

• A wide spectrum of rare syndromes manifesting in childhood is associated with an increased cancer risk. • For many of these syndromes, expert recommendations for management and tumor surveillance are available, although based on limited evidence.

WHAT IS NEW

• Evaluating current practice, our data attest significant shortcomings in tumor surveillance of children and adolescents with CPS even in a tertiary-care children's hospital. • We clearly advocate a systematic and consistent integration of tumor surveillance into daily practice.

Childhood Cancer Predisposition: An Overview for the General Pediatrician

Cancer predisposition syndromes (CPS), or genetic syndromes leading to increased cancer risk, are responsible for at least 10% of all childhood cancers. With advances in both tumor and germline sequencing, these syndromes have been uncovered both in patients with and without syndromic features and family history of cancer. Recognition of CPS in children and use of associated screening guidelines can improve morbidity and mortality from childhood cancer. Given the multidisciplinary approach needed for management of CPS, knowledge of clinical features and surveillance guidelines are essential for the general pediatrician. Pediatricians also play a vital role in anticipatory guidance regarding cancer prevention strategies and management of psychosocial stressors associated with ongoing screening. This article discusses 10 of the more common pediatric CPS, reasons to refer patients for CPS genetic testing and evaluation, and general cancer prevention strategies. [Pediatr Ann. 2022;51(1):e15-e21.].

Genetic conditions of short stature: A review of three classic examples

Noonan, Turner, and Prader-Willi syndromes are classical genetic disorders that are marked by short stature. Each disorder has been recognized for several decades and is backed by extensive published literature describing its features, genetic origins, and optimal treatment strategies. These disorders are accompanied by a multitude of comorbidities, including cardiovascular issues, endocrinopathies, and infertility. Diagnostic delays, syndrome-associated comorbidities, and inefficient communication among the members of a patient's health care team can affect a patient's well-being from birth through adulthood. Insufficient information is available to help patients and their multidisciplinary team of providers transition from pediatric to adult health care systems. The aim of this review is to summarize the clinical features and genetics associated with each syndrome, describe best practices for diagnosis and treatment, and emphasize the importance of multidisciplinary teams and appropriate care plans for the pediatric to adult health care transition.

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.

Rapid testing of candidate oncogenes and tumour suppressor genes in signal transduction and neoplastic transformation

The COSMIC database (version 94) lists 576 genes in the Cancer Gene Census which have a defined function as drivers of malignancy (oncogenes) or as tumour suppressors (Tier 1). In addition, there are 147 genes with similar functions, but which are less well characterised (Tier 2). Furthermore, next-generation sequencing projects in the context of precision oncology activities are constantly discovering new ones. Since cancer genes differ from their wild-type precursors in numerous molecular and biochemical properties and exert significant differential effects on downstream processes, simple assays that can uncover oncogenic or anti-oncogenic functionality are desirable and may precede more sophisticated analyses. We describe simple functional assays for PTPN11 (protein-tyrosine phosphatase, non-receptor-type 11)/SHP2 mutants, which are typically found in RASopathies and exhibit potential oncogenic activity. We have also designed a functional test for lysyl oxidase (LOX), a prototypical class II tumour suppressor gene whose loss of function may contribute to neoplastic transformation by RAS oncogenes. Moreover, we applied this test to analyse three co-regulated, RAS-responsive genes for transformation-suppressive activity. The integration of these tests into systems biology studies will contribute to a better understanding of cellular networks in cancer.

Cancer-related mortality among people with intellectual disabilities: A nationwide population-based cohort study

Background

Concerns have been raised about access to cancer screening and the timely receipt of cancer care for people with an intellectual disability (ID). However, knowledge about cancer mortality as a potential consequence of these disparities is still limited. This study, therefore, compared cancer‐related mortality patterns between people with and without ID.

Methods

A historical cohort study (2015‐2019) linked the Dutch adult population (approximately 12 million people with an ID prevalence of 1.45%) and mortality registries. Cancer‐related mortality was identified by the underlying cause of death (according to the chapter on neoplasms in the International Classification of Diseases, Tenth Revision). Observed mortality and calculated age‐ and sex‐standardized mortality ratios (SMRs) with 95% confidence intervals (CIs) were reported.

Results

There were 11,102 deaths in the ID population (21.7% cancer‐related; n = 2408) and 730,405 deaths in the general population (31.2%; n = 228,120) available for analysis. Cancer was noted as the cause of death more often among people with ID in comparison with the general population (SMR, 1.48; 95% CI, 1.42‐1.54), particularly in the young age groups. High‐mortality cancers included cancers within the national screening program (SMRs, 1.43‐1.94), digestive cancers (SMRs, 1.24‐2.56), bladder cancer (SMR, 2.07; 95% CI, 1.61‐2.54), and cancers of unknown primary (SMR, 2.48; 95% CI, 2.06‐2.89).

Conclusions

Cancer was reported as the cause of death approximately 1.5 times more often in people with ID compared with the general population. This mortality disparity may indicate adverse effects from inequalities in screening and cancer care experienced by people with ID.

Lay Summary

People with an intellectual disability (ID) may find it challenging to participate in cancer screening or to receive timely cancer care.

To understand potential consequences in terms of mortality, this study compared cancer‐related mortality between people with and without ID in the Netherlands.

Cancer was reported as the cause of death approximately 1.5 times more often among people with ID than others.

Because large differences were found that were related to screening cancers and cancers for which the primary tumor was unknown, this study's results raise concerns about equality in screening practices and cancer care for people with ID.

Cancer is reported as the cause of death approximately 1.5 times more often in people with an intellectual disability compared with those without one. Differences are particularly noted for deaths related to cancers within the national screening program and cancers of unknown primary.

Somatic Variation as an Incidental Finding in the Pediatric Next Generation Sequencing Era

The methodologic approach used in next-generation sequencing (NGS) affords a high depth of coverage in genomic analysis. Inherent in the nature of genomic testing, there exists potential for identifying genomic findings that are incidental or secondary to the indication for clinical testing, with the frequency dependent on the breadth of analysis and the tissue sample under study. The interpretation and management of clinically meaningful incidental genomic findings is a pressing issue particularly in the pediatric population. Our study describes a 16-mo-old male who presented with profound global delays, brain abnormality, progressive microcephaly, and growth deficiency, as well as metopic craniosynostosis. Clinical exome sequencing (ES) trio analysis revealed the presence of two variants in the proband. The first was a de novo variant in the PPP2R1A gene (c.773G > A, p.Arg258His), which is associated with autosomal dominant (AD) intellectual disability, accounting for the proband's clinical phenotype. The second was a recurrent hotspot variant in the CBL gene (c.1111T > C, p.Tyr371His), which was present at a variant allele fraction of 11%, consistent with somatic variation in the peripheral blood sample. Germline pathogenic variants in CBL are associated with AD Noonan syndrome–like disorder with or without juvenile myelomonocytic leukemia. Molecular analyses using a different tissue source, buccal epithelial cells, suggest that the CBL alteration may represent a clonal population of cells restricted to leukocytes. This report highlights the laboratory methodologic and interpretative processes and clinical considerations in the setting of acquired variation detected during clinical ES in a pediatric patient.

Patient engagement in the design of clinical research in Noonan syndrome spectrum disorders: a scoping review

Background

Noonan syndrome spectrum disorders are a group of disorders caused by mutations in several genes of the RAS/MAPK pathway. Because of a highly heterogeneity and variable phenotypical manifestations of the disorders, these children and adults have a variable number of symptoms. Inclusion of their perceived experience of their health and developmental problems in research (design) could contribute to increased relevance of the research process and outcomes. The aim of this study is to get insight in what way patients with a Noonan syndrome spectrum disorder have been involved in the research process in order to learn for future engagement practices.

Methods and results

To that end, the degree of engagement was measured by the eight levels of the participation ladder of Arnstein. Using a scoping review approach, 18 articles were selected in which patient engagement in the design of studies in patients with Noonan syndrome spectrum disorders was described over the past twenty years. Six of these articles reported engagement on the level of informing (level 3), 8 on the level of consultation (level 4), 2 on the level of placation (level 5)and 2 on the level of partnership (level 6).

Conclusions

The current results do show a positive albeit still modest development of patient engagement over the last few years. A promising way to stimulate engagement is aiming to yield insights in the most important patients’ needs by developing a patient guided research agenda. However, this is not automatically followed by patient engagement at higher levels of participation in subsequent research steps. For this reason, in the Netherlands for example, a Dutch Noonan syndrome spectrum disorders research agenda is being developed, in a collaboration between the Dutch Noonan Syndrome Foundation and national scientific and clinical professionals.

Germline Predisposition to Pediatric Cancer, from Next Generation Sequencing to Medical Care

Knowledge about genetic predisposition to pediatric cancer is constantly expanding. The categorization and clinical management of the best-known syndromes has been refined over the years. Meanwhile, new genes for pediatric cancer susceptibility are discovered every year. Our current work shares the results of genetically studying the germline of 170 pediatric patients diagnosed with cancer. Patients were prospectively recruited and studied using a custom panel, OncoNano V2. The well-categorized predisposing syndromes incidence was 9.4%. Likely pathogenic variants for predisposition to the patient's tumor were identified in an additional 5.9% of cases. Additionally, a high number of pathogenic variants associated with recessive diseases was detected, which required family genetic counseling as well. The clinical utility of the Jongmans MC tool was evaluated, showing a high sensitivity for detecting the best-known predisposing syndromes. Our study confirms that the Jongmans MC tool is appropriate for a rapid assessment of patients; however, the updated version of Ripperger T criteria would be more accurate. Meaningfully, based on our findings, up to 9.4% of patients would present genetic alterations predisposing to cancer. Notably, up to 20% of all patients carry germline pathogenic or likely pathogenic variants in genes related to cancer and, thereby, they also require expert genetic counseling. The most important consideration is that the detection rate of genetic causality outside Jongmans MC et al. criteria was very low.

Medical guidelines for Li-Fraumeni syndrome 2019, version 1.1

Li–Fraumeni syndrome (LFS) is a hereditary tumor that exhibits autosomal dominant inheritance. LFS develops in individuals with a pathogenic germline variant of the cancer-suppressor gene, TP53 (individuals with TP53 pathogenic variant). The number of individuals with TP53 pathogenic variant among the general population is said to be 1 in 500 to 20,000. Meanwhile, it is found in 1.6% (median value, range of 0–6.7%) of patients with pediatric cancer and 0.2% of adult patients with cancer. LFS is diagnosed by the presence of germline TP53 pathogenic variants. However, patients can still be diagnosed with LFS even in the absence of a TP53 pathogenic variant if the familial history of cancers fit the classic LFS diagnostic criteria. It is recommended that TP53 genetic testing be promptly performed if LFS is suspected. Chompret criteria are widely used for the TP53 genetic test. However, as there are a certain number of cases of LFS that do not fit the criteria, if LFS is suspected, TP53 genetic testing should be performed regardless of the criteria. The probability of individuals with TP53 pathogenic variant developing cancer in their lifetime (penetrance) is 75% for men and almost 100% for women. The LFS core tumors (breast cancer, osteosarcoma, soft tissue sarcoma, brain tumor, and adrenocortical cancer) constitute the majority of cases; however, various types of cancers, such as hematological malignancy, epithelial cancer, and pediatric cancers, such as neuroblastoma, can also develop. Furthermore, approximately half of the cases develop simultaneous or metachronous multiple cancers. The types of TP53 pathogenic variants and factors that modify the functions of TP53 have an impact on the clinical presentation, although there are currently no definitive findings. There is currently no cancer preventive agent for individuals with TP53 pathogenic variant. Surgical treatments, such as risk-reducing bilateral mastectomy warrant further investigation. Theoretically, exposure to radiation could induce the onset of secondary cancer; therefore, imaging and treatments that use radiation should be avoided as much as possible. As a method to follow-up LFS, routine cancer surveillance comprising whole-body MRI scan, brain MRI scan, breast MRI scan, and abdominal ultrasonography (US) should be performed immediately after the diagnosis. However, the effectiveness of this surveillance is unknown, and there are problems, such as adverse events associated with a high rate of false positives, overdiagnosis, and sedation used during imaging as well as negative psychological impact. The detection rate of cancer through cancer surveillance is extremely high. Many cases are detected at an early stage, and treatments are low intensity; thus, cancer surveillance could contribute to an improvement in QOL, or at least, a reduction in complications associated with treatment. With the widespread use of genomic medicine, the diagnosis of LFS is unavoidable, and a comprehensive medical care system for LFS is necessary. Therefore, clinical trials that verify the feasibility and effectiveness of the program, comprising LFS registry, genetic counseling, and cancer surveillance, need to be prepared.

Safety of growth hormone (GH) treatment in GH deficient children and adults treated for cancer and non-malignant intracranial tumors-a review of research and clinical practice

Individuals surviving cancer and brain tumors may experience growth hormone (GH) deficiency as a result of tumor growth, surgical resection and/or radiotherapy involving the hypothalamic-pituitary region. Given the pro-mitogenic and anti-apoptotic properties of GH and insulin-like growth factor-I, the safety of GH replacement in this population has raised hypothetical safety concerns that have been debated for decades. Data from multicenter studies with extended follow-up have generally not found significant associations between GH replacement and cancer recurrence or mortality from cancer among childhood cancer survivors. Potential associations with secondary neoplasms, especially solid tumors, have been reported, although this risk appears to decline with longer follow-up. Data from survivors of pediatric or adult cancers who are treated with GH during adulthood are scarce, and the risk versus benefit profile of GH replacement of this population remains unclear. Studies pertaining to the safety of GH replacement in individuals treated for nonmalignant brain tumors, including craniopharyngioma and non-functioning pituitary adenoma, have generally been reassuring with regards to the risk of tumor recurrence. The present review offers a summary of the most current medical literature regarding GH treatment of patients who have survived cancer and brain tumors, with the emphasis on areas where active research is required and where consensus on clinical practice is lacking.

Genetic and clinical heterogeneity in Korean patients with Rubinstein-Taybi syndrome

Background

Rubinstein–Taybi syndrome (RSTS) is a rare congenital malformation syndrome with clinical characteristics such as hypertrichosis, high arched eyebrows, large beaked nose, and broad thumbs and halluces. RSTS patients showed intellectual disability and health problems such as short stature, ophthalmologic abnormalities, congenital heart defects, genitourinary defects, and variable types of tumors. Although mutations in CREBBP and EP300 genes are associated with RSTS features, genetic causation is still unknown in 30% of patients.

Methods

We present clinical and molecular genetic characteristics of 25 unrelated Korean patients clinically diagnosed with RSTS. Sanger sequencing analysis and multiplex ligation‐dependent probe amplification for CREBBP in 25 patients and exome sequencing of CREBBP‐negative cases were performed in nine patients successively.

Results

Causative variants were identified in 20 (80%) patients: 16 (64%) in CREBBP and 4 (16%) in EP300. All the identified variants predict protein truncation (11 frameshift, 2 nonsense, 1 splicing‐site, and 6 large intragenic deletions); there are no repeatedly identified sequence variants. Four of the CREBBP and all four EP300 variants are novel. Intellectual disability was noted in 24/25 patients (96%); no difference was found between CREBBP and EP300 groups. One patient with a CREBBP variant (4%) had malignant tumor.

Conclusions

To date, this is the largest cohort of patients with RSTS including EP300‐related patients in Korea. Future large‐scale studies to find genetic mutation of molecularly unsolved patients and long‐term prospective studies are required to validate our results.

The potential oncogenic role of the RAS-like GTP-binding gene RIT1 in glioblastoma

Glioblastoma is the most common type of malignant brain tumors and the most feared cancer among adults. The poor prognosis among patients affected with this type of cancer is associated with its high-invasiveness and the lack of successful therapies. A comprehensive understanding for the early molecular mechanisms in glioblastoma would definitely enhance the diagnosis and the treatment strategies. Deregulated expression of key genes that are known to be involved in early neurogenesis could be the instigator of brain tumorigenesis. Ras Like Without CAAX 1 (RIT1) gene that encodes an unusual "orphan" GTPase protein belongs to this category of critical genes that are known to be involved in controlling sequential proliferation and differentiation of adult hippocampal neural progenitor cells. In this study, we surveyed RIT1 gene expression by in-silico approaches to determine its spatio-temporal pattern in glioblastoma. Our results revealed a significant and progressive upregulation of RIT1 mRNA levels in various publicly available datasets. RIT1 expression ranked among the top upregulated genes in glioblastoma cohorts and it correlated with poor overall survival. Genetic and epigenetic analysis of RIT1 didn't reveal any significant aberration that could underlie its deregulated expression. Yet, our results highlighted the possibility of its activity to be transcriptionally controlled by STAT3, one of the main players in the onset of glioblastoma. In conclusion, our study presented for the first time a potential oncogenic role for RIT1 in glioblastoma. Knowing that the RAS superfamily of proteins has created an evolution in the cancer field, RIT1 should be added to this list through further investigations on its possible usage as a biomarker and therapeutic target in glioblastoma.

Etiology and Treatment of Growth Delay in Noonan Syndrome

Noonan syndrome is characterized by multiple phenotypic features, including growth retardation, which represents the main cause of consultation to the clinician. Longitudinal growth during childhood and adolescence depends on several factors, among them an intact somatotrophic axis, which is characterized by an adequate growth hormone (GH) secretion by the pituitary, subsequent binding to its receptor, proper function of the post-receptor signaling pathway for this hormone (JAK-STAT5b and RAS/MAPK), and ultimately by the production of its main effector, insulin like growth factor 1 (IGF-1). Several studies regarding the function of the somatotrophic axis in patients with Noonan syndrome and data from murine models, suggest that partial GH insensitivity at a post-receptor level, as well as possible derangements in the RAS/MAPK pathway, are the most likely causes for the growth failure in these patients. Treatment with recombinant human growth hormone (rhGH) has been used extensively to promote linear growth in these patients. Numerous treatment protocols have been employed so far, but the published studies are quite heterogeneous regarding patient selection, length of treatment, and dose of rhGH utilized, so the true benefit of GH therapy is somewhat difficult to establish. This review will discuss the possible etiologies for the growth delay, as well as the outcomes following rhGH treatment in patients with Noonan syndrome.

Atypical, severe hypertrophic cardiomyopathy in a newborn presenting Noonan syndrome harboring a recurrent heterozygous MRAS variant

Noonan syndrome (NS) is a Mendelian phenotype, member of a group of disorders sharing neurocardiofaciocutaneous involvement, known as RASopathies, caused by germline variants in genes coding for components of the RAS/MAPK signaling pathway. Recently, a novel gene of the RAS family (MRAS) was reported to be associated with NS in five children, all of them presenting, among the cardinal features of NS, the same cardiac finding, hypertrophic cardiomyopathy (HCM). We report on a 2-month-old infant boy also presenting this cardiac anomaly that evolved to a fatal outcome after a surgical myectomy. In addition, a thick walled left ventricle apical aneurysm, rarely described in NS, was also disclosed. Next-generation sequencing revealed a missense, previously reported variant in MRAS (p.Thr68Ile). This report reinforces the high frequency of HCM among individuals harboring MRAS variants, contrasting to the 20% overall prevalence of this cardiac anomaly in NS. Thus, these preliminary data suggest that variants in MRAS per se are high risk factors for the development of an early, severe HCM, mostly of them with left ventricle outflow tract obstruction, with poor prognosis. Because of the severity of the cardiac involvement, other clinical findings could not be addressed in detail. Therefore, long-term follow-up of these individuals and further descriptions are required to fully understand the complete phenotypic spectrum of NS associated with MRAS germline variants, including if these individuals present an increased risk for cancer.

Juvenile xanthogranuloma in Noonan syndrome

Noonan syndrome (NS) is one of the common RASopathies. While the clinical phenotype in NS is variable, it is typically characterized by distinctive craniofacial features, cardiac defects, reduced growth, bleeding disorders, learning issues, and an increased risk of cancer. Several different genes cause NS, all of which are involved in the Ras/mitogen-activated protein kinase (Ras/MAPK) pathway. Juvenile xanthogranuloma (JXG) is an uncommon, proliferative, self-limited cutaneous disorder that affects young individuals and may be overlooked or misdiagnosed due to its transient nature. A RASopathy that is known to be associated with JXG is neurofibromatosis type 1 (NF1). JXG in NF1 has also been reported in association with a juvenile myelomonocytic leukemia (JMML). As RASopathies, both NS and NF1 have an increased incidence of JMML. We report a 10-month-old female with NS who has a PTPN11 pathogenic variant resulting in a heterozygous SHP2 p.Y62D missense mutation. She was found to have numerous, small, yellow-pink smooth papules that were histopathologically confirmed to be JXG. In understanding the common underlying pathogenetic dysregulation of the Ras/MAPK pathway in both NS and NF1, this report suggests a possible molecular association for why NS individuals may be predisposed to JXG.