A Case of Noonan Syndrome and Kyrle Disease: Casualty or Causality?

A 39-year-old Caucasian woman affected by Noonan Syndrome (NS) mutated in RAF1 was referred to us with itchy lesions on her limbs that had appeared two months earlier. Clinically, there were multiple umbilicated papules with a hyperkeratotic central plug, localized on the upper and lower limbs (Figure 1, a-b). The patient had no personal history of diabetes mellitus or chronic renal failure, but suffered from hypertrophic cardiomyopathy. Blood tests showed no abnormalities. On histological examination of a skin lesion, an ectatic hair follicle with a hyperkeratotic ostium was observed with fragments of hair, inflammatory cells, and epidermal perforation. A final diagnosis of Kyrle disease (KD) was established. The patient underwent narrowband UVB (NB-UVB) phototherapy with residual atrophic scars (Figure 1, c-d), but with a complete and long-lasting resolution of symptoms. KD belongs to perforating dermatoses (PD), a heterogeneous group of skin diseases characterized by the transepidermal elimination of dermal components. Despite the classification of PD still being under debate, four primary forms are traditionally recognized: reactive perforating collagenosis, elastosis perforans serpiginosum, perforating folliculitis, and KD (1). The typical skin manifestation of KD is an eruption of dome-shaped papules and nodules, with a whitish central keratotic plug, mainly localized on the extremities and the buttocks. Described by Kyrle in 1916, KD is frequently associated with systemic diseases, especially chronic renal failure and diabetes mellitus. Other associated conditions include chronic hepatic disease, internal malignancies, and congestive heart disease (1). Despite the absence of a consensus, the control of the underlying disease remains the first therapeutic target. Both topical (keratolytics, retinoids, and corticosteroids) and systemic treatments (corticosteroids, retinoids, antibiotics, and phototherapy) have been reported to control skin manifestations (2). In our experience, NB-UVB is an effective option as first-line therapy in case of diffuse lesions, both in KD and in other PD (3). NS is a relatively common RASopathy, a heterogenous group of genetic diseases characterized by a defect of the Ras-mitogen-activated protein kinase (Ras-MAPK) pathway, with an estimated prevalence of 1/1000-2500. PTPN11 is the most frequent mutated gene, accounting for 50% of cases, but more than ten genes have been identified as causing NS (4). Classical features include a distinctive facial dysmorphism, short stature, pulmonic stenosis, and other anomalies of different organs. The skin is commonly involved. Keratinization disorders and hair abnormalities such as keratosis pilaris, ulerythema ophryogenes, wavy or curly hair, and scarce scalp hair, are often described. Other cutaneous signs include easy bruising, skin hyperlaxity, multiple lentigines, and café-au-lait spots (5). To the best of our knowledge, no cases of KD in patients with NS have been previously reported to date. The exact etiopathogenesis of KD is not clear, but it has been hypothesized that systemic diseases, such as diabetes and chronic renal failure, can cause a deposit of substances or dermis alterations, which triggers the inflammatory process with subsequent transepidermal extrusion (1). In our patient, we ruled out all the causes commonly associated with KD. It is however possible that this manifestation could be a direct result of the patient's illness. Our patient suffered from diffuse keratosis pilaris, and an abnormal epidermal keratinization with a secondary inflammatory dermic response is among the suggested possible pathogenetic mechanisms of KD (1). On the other hand, the hyperlaxity and fragility of the skin typical of NS suggest the presence of altered connective tissue, which could trigger an abnormal keratinization and, subsequently, the transepidermal extrusion, as well as perforating elastosis, which is associated with genetic connective tissue diseases (1). Moreover, our patient suffered from a cardiac disease, another condition associated with KD (5). Although these explanations have their appeal, there is currently insufficient evidence of a link between KD and NS, and it will be necessary to collect additional data to confirm this hypothesis.

Dermatological manifestations, management, and care in RASopathies.

RASopathies are rare genetic disorders caused by germline pathogenic variants in genes belonging to the RAS/MAPK pathway, which signals cell proliferation, differentiation, survival and death. The dysfunction of such signaling pathway causes syndromes with overlapping clinical manifestations. Skin and adnexal lesions are the cardinal clinical signs of RASopathies, such as cardiofaciocutaneous syndrome, Noonan syndrome with multiple lentigines, formerly known as LEOPARD syndrome, Costello syndrome, neurofibromatosis (NF1), Legius syndrome, Noonan-like syndrome with loose anagen hair (NSLH) and Noonan syndrome. As NF1, one of the most common RASopathies, described in 1882, has its clinical features well delineated, we will focus on the dermatological diagnosis, management and care of non-NF1 RASopathies, which are less known and more recently described. Dermatological manifestations are important clinical diagnostic elements that can aid differential diagnosis among RASopathies. They can affect dermis and epidermis, causing pigmented lesions (melanocytic nevi, café-au-lait spots, and lentigines), hyperkeratosis (keratosis pilaris, ulerythema ophryogenes, and palmoplantar keratosis) or hyperplasia. To date there are rare known links to malignancy, but oftentimes skin lesions require close attention because they can highly affect quality of life.

Management of nutritional and gastrointestinal issues in RASopathies: A narrative review.

Noonan, Costello, and cardio-facio-cutaneous syndrome are neurodevelopmental disorders belonging to the RASopathies, a group of syndromes caused by alterations in the RAS/MAPK pathway. They are characterized by similar clinical features, among which feeding difficulties, growth delay, and gastro-intestinal disorders are frequent, causing pain and discomfort in patients. Hereby, we describe the main nutritional and gastrointestinal issues reported in individuals with RASopathies, specifically in Noonan syndrome, Noonan syndrome-related disorders, Costello, and cardio-facio-cutaneous syndromes. Fifty percent of children with Noonan syndrome may experience feeding difficulties that usually have a spontaneous resolution by the second year of life, especially associated to genes different than PTPN11 and SOS1. More severe manifestations often require artificial enteral nutrition in infancy are observed in Costello syndrome, mostly associated to c.34G>A substitution in the HRAS gene. In cardio-facio-cutaneous syndrome feeding issues are usually present (90-100% of cases), especially in individuals carrying variants in BRAF, MAP2K1, and MAP2K2 genes, and artificial enteral intervention, even after scholar age, may be required. Moreover, disorders associated with gastrointestinal dysmotility as gastro-esophageal reflux and constipation are commonly reported in all the above-mentioned syndromes. Given the impact on growth and on the quality of life of these patients, early evaluation and prompt personalized management plans are fundamental.

Neuropsychological features in RASopathies: A pilot study on parent training program involving families of children with Noonan syndrome.

Noonan syndrome (NS) is a clinical variable multisystem disorder caused by mutations in genes encoding proteins involved in the RAS/mitogen-activated protein kinase signaling pathway. NS is characterized by a distinctive facies, short stature, and congenital heart defects. Psychomotor delay, learning difficulties, and social deficits are also common. Furthermore, behavioral and attention problems can be reckoned as a key symptom in NS, with functioning resembling the patterns observed in attention deficit hyperactivity disorder (ADHD). The complex behavioral phenotype has great impact on the quality of life and raises demanding management issues also for patients' families. Parent management training (PMT) is recommended as first-line treatment for ADHD; however, no study has been performed to test the efficacy of PMT in NS, thus far. The aim of this pilot study is the implementation and evaluation of a PMT dedicated to NS families. Parents of seven children with NS were recruited and underwent to a 10-session PMT. Three different questionnaires were administered to both parents: Conners Parent Rating Scales, Parenting Stress Index Short Form (PSI-SF), and Alabama Parenting Questionnaire (APQ). Our findings on this first small cohort of families indicate that positive perception and satisfaction about the child and the interaction with him increased in mothers after the intervention, as measured respectively by PSI-SF difficult child (DC) and PSI-SF parent-child dysfunctional interaction (PCDI), while mothers' level of stress decreased after the PMT, as indicated by PSI-SF total scores. Furthermore, APQ positive parenting, which measures behaviors of positive relationship with the child, increased in mothers after the intervention. Statistical analysis on fathers' questionnaires did not show significant differences after the PMT sessions. This pilot study suggests that PMT is a promising intervention for parents of NS children with behavioral and ADHD symptoms. Changes in mothers' attitudes and distress indicate that behaviorally oriented programs may help parents to manage with NS phenotype.

Noonan syndrome: improving recognition and diagnosis.

Noonan syndrome (NS) is a mostly dominantly inherited disorder affecting 1:1000 to 1:2500 live births. The phenotype varies in severity and can involve multiple organ systems over a patient's lifetime. Diagnosis is based on a combination of features, including typical facial features, short stature, skeletal abnormalities, presence of cardiac defects, mild developmental delay, cryptorchidism, lymphatic dysplasia and a family history of NS. The phenotype varies from oligosymptomatic adults without significant medical issues to severely affected neonates with life-threatening heart disease. Early, accurate diagnosis is important for individualised management and to optimise developmental and long-term outcomes, but mildly affected patients often go undiagnosed for both healthcare provider (HCP)-related and patient-related reasons. Lack of awareness of NS among HCPs means that some do not recognise the condition, particularly in mildly affected patients and families. Some families do not want to receive a diagnosis that medicalises a condition that may account for family traits (eg, distinctive facial features and short stature), particularly when a child's physical and cognitive development may be satisfactory. As for any condition with lifelong effects on multiple organ systems, a multidisciplinary approach provides the best care. It is proposed that increasing awareness of NS among non-specialist HCPs and other professionals could help direct a parent/carer to seek specialist advice and increase the number of NS diagnoses, with the potential to optimise lifelong patient outcomes. Non-specialists do not need to become experts in either diagnosis or treatment; however, early recognition of NS and referral to an appropriate specialist is important.

Management of cardiac aspects in children with Noonan syndrome - results from a European clinical practice survey among paediatric cardiologists.

BACKGROUND: The majority of children with Noonan syndrome (NS) or other diseases from the RASopathy spectrum suffer from congenital heart disease. This study aims to survey cardiac care of this patient cohort within Europe. METHODS: A cross-sectional exploratory survey assessing the treatment and management of patients with NS by paediatric endocrinologists, cardiologists and clinical geneticists was developed. This report details responses of 110 participating paediatric cardiologists from multiple countries. RESULTS: Most paediatric cardiologists responding to the questionnaire were associated with university hospitals, and most treated <10 patients/year with congenital heart disease associated with the NS spectrum. Molecular genetic testing for diagnosis confirmation was initiated by 81%. Half of the respondents reported that patients with NS and congenital heart disease typically present <1y of age, and that a large percentage of affected patients require interventions and pharmacotherapy early in life. A higher proportion of infant presentation and need for pharmacotherapy was reported by respondents from Germany and Sweden than from France and Spain (p = 0.031; p = 0.014; Fisher's exact test). Older age at first presentation was reported more from general hospitals and independent practices than from university hospitals (p = 0.031). The majority of NS patients were followed at specialist centres, but only 37% reported that their institution offered dedicated transition clinic to adult services. Very few NS patients with hypertrophic cardiomyopathy (HCM) were reported to carry implantable cardioverter defibrillators for sudden cardiac death prevention. Uncertainty was evident in regard to growth hormone treatment in patients with NS and co-existing HCM, where 13% considered it not a contra-indication, 24% stated they did not know, but 63% considered HCM either a possible (20%) or definite (15%) contraindication, or a cause for frequent monitoring (28%). Regarding adverse reactions for patients with NS on growth hormone therapy, 5/19 paediatric cardiology respondents reported a total of 12 adverse cardiac events. CONCLUSIONS: Congenital heart disease in patients with NS or other RASopathies is associated with significant morbidity during early life, and specialty centre care is appropriate. More research is needed regarding the use of growth hormone in patients with NS with congenital heart disease, and unmet medical needs have been identified.

European Medical Education Initiative on Noonan syndrome: A clinical practice survey assessing the diagnosis and clinical management of individuals with Noonan syndrome across Europe.

INTRODUCTION: Noonan syndrome (NS) is a rare genetic disorder caused by mutations in genes encoding components of the RAS/mitogen-activated protein kinase (MAPK) signalling pathway. Patients with NS exhibit certain characteristic features, including cardiac defects, short stature, distinctive facial appearance, skeletal abnormalities, cognitive deficits, and predisposition to certain cancers. Here, a clinical practice survey was developed to learn more about differences in the diagnosis and management of this disease across Europe. The aim was to identify gaps in the knowledge and management of this rare disorder. MATERIALS AND METHODS: The European Medical Education Initiative on NS, which comprised a group of 10 experts, developed a 60-question clinical practice survey to gather information from European physicians on the diagnosis and clinical management of patients with diseases in the NS phenotypic spectrum. Physicians from three specialities (clinical genetics, paediatric endocrinology, paediatric cardiology) were invited to complete the survey by several national and European societies. Differences in answers provided by respondents between specialities and countries were analysed using contingency tables and the Chi-Squared test for independence. The Friedman's test was used for related samples. RESULTS: Data were analysed from 364 respondents from 20 European countries. Most respondents came from France (21%), Spain (18%), Germany (16%), Italy (15%), United Kingdom (8%) and the Czech Republic (6%). Respondents were distributed evenly across three specialities: clinical genetics (30%), paediatric endocrinology (40%) and paediatric cardiology (30%). Care practices were generally aligned across the countries participating in the survey. Delayed diagnosis did not emerge as a critical issue, but certain unmet needs were identified, including transition of young patients to adult medical services and awareness of family support groups. CONCLUSION: Data collected from this survey provide a comprehensive summary of the diagnosis and clinical management practices for patients with NS across different European countries.

Therapy-related Myeloid Neoplasms in Children: A Single-institute Study.

Therapy-related myeloid neoplasm (t-MN) in the pediatric population is not well characterized. We studied 12 pediatric patients diagnosed with t-MN in our institution since 2006. The median age at the t-MN diagnoses was 14.8 years (range, 9 to 20 y). The primary malignancies included 9 solid tumors and 3 hematopoietic malignancies. Rhabdomyosarcoma (n=4) was the most common primary malignancy. Five of the 9 patients with solid tumors and all 3 patients with hematopoietic malignancies had primary neoplasms involving bone marrow. The median latency period was 5.2 years (range, 1.8 to 13.8 y). Thrombocytopenia was present in all patients at the t-MN diagnoses. Complete or partial monosomy of chromosome 5 or 7 were the 2 most common cytogenetic abnormalities. A quarter of patients demonstrated a genetic predisposition to t-MN: 1 with Li-Fraumeni syndrome with a germline TP53 R248Q mutation, 1 with Noonan syndrome with a somatic mutation (PTPN11 S502T), and 1 with a constitutive chromosomal translocation [t(X;9)(p22;q34)] and a germline TP53 L130V mutation. Outcomes remain poor. Two patients survived 3 and 5.1 years after hematopoietic stem cell transplantation.

RASopathies.

RASopathies are a group of disorders characterized by mutations in the RAS-MAPK pathway. RAS-MAP signaling plays a critical role in cell differentiation, proliferation, and survival. Germline mutations can result in distinctive syndromes, including Noonan syndrome, Costello syndrome, and neurofibromatosis type 1. Mosaic RASopathies can present as localized cutaneous lesions like epidermal nevi and nevus sebaceous, or more extensive conditions such as encephalocraniocutaneous lipomatosis. We review the heterogenous presentation of RAS mutations, discuss new targeted therapies, and highlight areas of uncertainty, including carcinogenesis risk and appropriate screening.

Abnormal pulmonary lymphatic flow in patients with paediatric pulmonary lymphatic disorders: Diagnosis and treatment.

Pulmonary lymphatic disorders are characterized by the presence of the abnormal lymphatic tissues in the thoracic cavity, presenting clinically as chylothorax, chylopericardium, chyloptysis, interstitial lung disease and plastic bronchitis. These conditions include: neonatal chylothorax, cardiac and non-cardiac plastic bronchitis, non-traumatic chylothorax, post congenital cardiac surgery chylothorax and complex lymphatic malformations. Recently developed lymphatic imaging techniques, such as intranodal lymphangiography and dynamic contrast enhanced magnetic resonance lymphangiography demonstrated abnormal pulmonary lymphatic flow from thoracic duct into pulmonary parenchyma as a pathophysiological mechanism of these diseases. Novel minimally invasive lymphatic interventions, such as thoracic duct embolization, interstitial lymphatic embolization and surgical lympho-venous anastomosis, provide an effective treatment of these conditions.

Intronic CRISPR Repair in a Preclinical Model of Noonan Syndrome-Associated Cardiomyopathy.

BACKGROUND: Noonan syndrome (NS) is a multisystemic developmental disorder characterized by common, clinically variable symptoms, such as typical facial dysmorphisms, short stature, developmental delay, intellectual disability as well as cardiac hypertrophy. The underlying mechanism is a gain-of-function of the RAS-mitogen-activated protein kinase signaling pathway. However, our understanding of the pathophysiological alterations and mechanisms, especially of the associated cardiomyopathy, remains limited and effective therapeutic options are lacking. METHODS: Here, we present a family with two siblings displaying an autosomal recessive form of NS with massive hypertrophic cardiomyopathy as clinically the most prevalent symptom caused by biallelic mutations within the leucine zipper-like transcription regulator 1 (LZTR1). We generated induced pluripotent stem cell-derived cardiomyocytes of the affected siblings and investigated the patient-specific cardiomyocytes on the molecular and functional level. RESULTS: Patients' induced pluripotent stem cell-derived cardiomyocytes recapitulated the hypertrophic phenotype and uncovered a so-far-not-described causal link between LZTR1 dysfunction, RAS-mitogen-activated protein kinase signaling hyperactivity, hypertrophic gene response and cellular hypertrophy. Calcium channel blockade and MEK inhibition could prevent some of the disease characteristics, providing a molecular underpinning for the clinical use of these drugs in patients with NS, but might not be a sustainable therapeutic option. In a proof-of-concept approach, we explored a clinically translatable intronic CRISPR (clustered regularly interspaced short palindromic repeats) repair and demonstrated a rescue of the hypertrophic phenotype. CONCLUSIONS: Our study revealed the human cardiac pathogenesis in patient-specific induced pluripotent stem cell-derived cardiomyocytes from NS patients carrying biallelic variants in LZTR1 and identified a unique disease-specific proteome signature. In addition, we identified the intronic CRISPR repair as a personalized and in our view clinically translatable therapeutic strategy to treat NS-associated hypertrophic cardiomyopathy.

Síndrome de Noonan: actualización genética, clínica y de opciones terapéuticas / Noonan syndrome: genetic and clinical update and treatment options

El síndrome de Noonan (SN) es una enfermedad de origen genético relativamente frecuente cuyas manifestaciones fundamentales son la talla baja, la cardiopatía congénita y un fenotipo facial característico. La causa del síndrome de Noonan y de otras enfermedades clínicamente solapadas como el síndrome de Noonan con lentiginosis múltiple (anteriormente llamado síndrome LEOPARD), el cardiofaciocutáneo o el síndrome de Costello, son mutaciones en genes que codifican para proteínas de la vía de señalización de las RAS-MAPKinasas. Debido a este sustrato común este grupo de enfermedades son denominadas colectivamente «rasopatías». A pesar de los avances genéticos de las últimas décadas, cerca de 20% de pacientes no tienen causa genética identificada, y el diagnóstico sigue siendo clínico. El síndrome de Noonan se caracteriza por una alta heterogeneidad clínica y genética, con afectación variable, y cambiante con la edad, de múltiples órganos y sistemas. Debido a esta variabilidad es fundamental que los médicos involucrados en su cuidado estén familiarizados con sus manifestaciones y conozcan las recomendaciones de seguimiento, incluido el seguimiento del crecimiento y desarrollo. Hasta la fecha los escasos datos de crecimiento con GH a talla adulta dan resultados de ganancia de talla moderados, semejantes a los obtenidos en el síndrome de Turner. La hiperactivación de la vía RAS-MAPK como base común de esta familia de enfermedades brinda una oportunidad única para el desarrollo de tratamientos dirigidos a la etiología de estos trastornos

Noonan syndrome (NS) is a relatively common genetic condition characterised by short stature, congenital heart defects, and distinctive facial features. NS and other clinically overlapping conditions such as NS with multiple lentigines (formerly called LEOPARD syndrome), cardiofaciocutaneous syndrome, or Costello syndrome, are caused by mutations in genes encoding proteins of the RAS-MAPKinases pathway. Because of this shared mechanism, these conditions have been collectively termed «RASopathies». Despite the recent advances in molecular genetics, nearly 20% of patients still lack a genetic cause, and diagnosis is still made mainly on clinical grounds. NS is a clinically and genetically heterogeneous condition, with variable expressivity and a changing phenotype with age, and affects multiple organs and systems. Therefore, it is essential that physicians involved in the care of these patients are familiarised with their manifestations and the management recommendations, including management of growth and development. Data on growth hormone treatment efficacy are sparse, and show a modest response in height gains, similar to that observed in Turner syndrome. The role of RAS/MAPK hyper-activation in the pathophysiology of this group of disorders offers a unique opportunity for the development of targeted approaches

[Noonan syndrome: genetic and clinical update and treatment options]. / Síndrome de Noonan: actualización genética, clínica y de opciones terapéuticas.

Noonan syndrome (NS) is a relatively common genetic condition characterised by short stature, congenital heart defects, and distinctive facial features. NS and other clinically overlapping conditions such as NS with multiple lentigines (formerly called LEOPARD syndrome), cardiofaciocutaneous syndrome, or Costello syndrome, are caused by mutations in genes encoding proteins of the RAS-MAPKinases pathway. Because of this shared mechanism, these conditions have been collectively termed «RASopathies¼. Despite the recent advances in molecular genetics, nearly 20% of patients still lack a genetic cause, and diagnosis is still made mainly on clinical grounds. NS is a clinically and genetically heterogeneous condition, with variable expressivity and a changing phenotype with age, and affects multiple organs and systems. Therefore, it is essential that physicians involved in the care of these patients are familiarised with their manifestations and the management recommendations, including management of growth and development. Data on growth hormone treatment efficacy are sparse, and show a modest response in height gains, similar to that observed in Turner syndrome. The role of RAS/MAPK hyper-activation in the pathophysiology of this group of disorders offers a unique opportunity for the development of targeted approaches.

[Clinical practice guidelines for Noonan syndrome].

Noonan syndrome is a common genetic disease characterized by peculiar face, short stature, congenital heart disease and thoracic deformity. The pathogenesis of Noonan syndrome is mainly related to abnormal Ras-MAPK signal pathway which involves more than 16 genes including (PTPN11, SOS1, RAF1)] and KRAS. At present, there is a lack of experience in the diagnosis and treatment of Noonan syndrome in China. This guideline has summarized the clinical manifestation, pathogenesis, diagnostic criteria and treatment for Noonan syndrome, with an aim to improve the diagnostic level and clinical management of patients with this syndrome.

[A case report of Noonan syndrome diagnosed in primary healthcare]. / Reporte de un caso de síndrome de Noonan diagnosticado en atención primaria.

Noonan syndrome is an autosomal dominant inherited disorder with variable phenotypic expression. It belongs to the group of diseases known as RASopathies, which are characterized by mutations in the RAS genes. Patients develop symptoms such as facial dysmorphism, short stature, congenital heart disease, musculoskeletal disorders and mental retardation. In this article, we report a case of Noonan syndrome in a 14-year-old patient, diagnosed in a primary health center in Ecuador. The syndrome was identified through clinical diagnosis, after which the patient was referred to the secondary and tertiary levels for specialized care.

El síndrome de Noonan es un trastorno genético de herencia autosómica dominante, de expresión fenotípica variable. Pertenece al grupo de las enfermedades conocidas como rasopatías, trastornos producido por las mutaciones en los genes RAS. Los pacientes desarrollan síntomas como dismorfismo facial, talla baja, enfermedad cardíaca congénita, alteraciones músculos esqueléticas y discapacidad intelectual. En el presente reporte, se describe un caso de diagnóstico del síndrome de Noonan en un paciente de 14 años, realizado a nivel de atención primaria en Ecuador. El síndrome se identificó mediante diagnóstico clínico, permitiendo su derivación al segundo y tercer nivel de salud para una atención especializada.

Congenital heart defects in Noonan syndrome: Diagnosis, management, and treatment.

Noonan syndrome is a pleomorphic genetic disorder, in which a high percentage of affected individuals have cardiovascular involvement, most prevalently various forms of congenital heart disease (i.e., pulmonary valve stenosis, septal defects, left-sided lesions, and complex forms with multiple anomalies). Care includes attentiveness to several comorbidities, some directly impacting cardiac management (bleeding diatheses and lymphatic anomalies). More than 50% of patients with Noonan syndrome harbor PTPN11 pathogenic variation, which results in hyperactivation of RAS/mitogen-activated protein kinase signaling. Several other disease genes with similar biological effects have been uncovered for NS and phenotypically related disorders, collectively called the RASopathies. Molecular diagnosis with gene resequencing panels is now widely available, but phenotype variability and in some cases, subtlety, continues to make identification of Noonan syndrome difficult. Until genetic testing becomes universal for patients with congenital heart disease, alertness to Noonan syndrome's broad clinical presentations remains crucial. Genotype-phenotype associations for Noonan syndrome enable better prognostication for affected patients when a molecular diagnosis is established. We still lack Noonan syndrome-specific treatment; however, newly developed anticancer RAS pathway inhibitors could fill that gap if safety and efficacy can be established for indications such as pulmonary valve stenosis.

Advancing RAS/RASopathy therapies: An NCI-sponsored intramural and extramural collaboration for the study of RASopathies.

RASopathies caused by germline pathogenic variants in genes that encode RAS pathway proteins. These disorders include neurofibromatosis type 1 (NF1), Noonan syndrome (NS), cardiofaciocutaneous syndrome (CFC), and Costello syndrome (CS), and others. RASopathies are characterized by heterogenous manifestations, including congenital heart disease, failure to thrive, and increased risk of cancers. Previous work led by the NCI Pediatric Oncology Branch has altered the natural course of one of the key manifestations of the RASopathy NF1. Through the conduct of a longitudinal cohort study and early phase clinical trials, the MEK inhibitor selumetinib was identified as the first active therapy for the NF1-related peripheral nerve sheath tumors called plexiform neurofibromas (PNs). As a result, selumetinib was granted breakthrough therapy designation by the FDA for the treatment of PN. Other RASopathy manifestations may also benefit from RAS targeted therapies. The overall goal of Advancing RAS/RASopathy Therapies (ART), a new NCI initiative, is to develop effective therapies and prevention strategies for the clinical manifestations of the non-NF1 RASopathies and for tumors characterized by somatic RAS mutations. This report reflects discussions from a February 2019 initiation meeting for this project, which had broad international collaboration from basic and clinical researchers and patient advocates.

Reporte de un caso de síndrome de Noonan diagnosticado en atención primaria / A case report of Noonan syndrome diagnosed in primary healthcare

El síndrome de Noonan es un trastorno genético de herencia autosómica dominante, de expresión fenotípica variable. Pertenece al grupo de las enfermedades conocidas como rasopatías, trastornos producido por las mutaciones en los genes RAS. Los pacientes desarrollan síntomas como dismorfismo facial, talla baja, enfermedad cardíaca congénita, alteraciones músculos esqueléticas y discapacidad intelectual. En el presente reporte, se describe un caso de diagnóstico del síndrome de Noonan en un paciente de 14 años, realizado a nivel de atención primaria en Ecuador. El síndrome se identificó mediante diagnóstico clínico, permitiendo su derivación al segundo y tercer nivel de salud para una atención especializada.

Noonan syndrome is an autosomal dominant inherited disorder with variable phenotypic expression. It belongs to the group of diseases known as RASopathies, which are characterized by mutations in the RAS genes. Patients develop symptoms such as facial dysmorphism, short stature, congenital heart disease, musculoskeletal disorders and mental retardation. In this article, we report a case of Noonan syndrome in a 14-year-old patient, diagnosed in a primary health center in Ecuador. The syndrome was identified through clinical diagnosis, after which the patient was referred to the secondary and tertiary levels for specialized care.