Function and disability in children with Costello syndrome and Cardiofaciocutaneous syndrome

The Cardiofaciocutaneous Syndrome: From Genetics to Prognostic-Therapeutic Implications

Cardiofaciocutaneous (CFC) syndrome is one of the rarest RASopathies characterized by multiple congenital ectodermal, cardiac and craniofacial abnormalities with a mild to severe ocular, gastrointestinal and neurological involvement. It is an autosomal dominant syndrome, with complete penetrance, caused by heterozygous pathogenic variants in the genes BRAF, MAP2K1/MEK1, MAP2K2/MEK2, KRAS or, rarely, YWHAZ, all part of the RAS-MAPK pathway. This pathway is a signal transduction cascade that plays a crucial role in normal cellular processes such as cell growth, proliferation, differentiation, survival, metabolism and migration. CFC syndrome overlaps with Noonan syndrome, Costello syndrome, neurofibromatosis type 1 and Legius syndrome, therefore making the diagnosis challenging. Neurological involvement in CFC is more severe than in other RASopathies. Phenotypic variability in CFC patients is related to the specific gene affected, without a recognized genotype-phenotype correlation for distinct pathogenic variants. Currently, there is no specific treatment for CFC syndrome. Encouraging zebrafish model system studies suggested that, in the future, MEK inhibitors could be a suitable treatment of progressive phenotypes of CFC in children. A multidisciplinary care is necessary for appropriate medical management.

Systematic ophthalmologic evaluation in cardio-facio-cutaneous syndrome: A genotype-endophenotype correlation

Cardio-facio-cutaneous syndrome (CFCS) is a rare genetic disorder belonging to the RASopathies, a group of developmental syndromes caused by upregulated RAS/MAPK signaling. Pathogenic variants affecting four genes, KRAS, BRAF, MAP2K1 and MAP2K2, encoding core signal transducers of the pathway, underlie the condition. Major clinical features include a distinctive facies, ectodermal and cardiac anomalies, reduced postnatal growth, intellectual disability, and musculoskeletal abnormalities. Similar to other RASopathies, reports of visual impairment, high refractive error, optic nerve pallor, and other ocular abnormalities have been anecdotally reported in the literature. The aim of our study is to report the prevalence of ophthalmologic abnormalities in a large monocentric cohort of individuals affected by CFCS and explore the occurrence of genotype-endophenotype correlations in this series of patients. We observed that BRAF mutations are associated to a higher prevalence of anisometropia >3D (11.8% vs. 0%) and high astigmatism (29.4% vs. 0%; both p < 0.001) while patients with mutations in other genes had a significantly higher prevalence of myopia >6 D (60% vs. 5.9%; p = 0.012). Pale optic disc was associated with higher prevalence of inferior oblique muscle (IO) overaction (33.3% vs. 0%) and lower prevalence of ptosis (0% vs. 11.8%; both p < 0.001). Combined exotropia, IO overaction and nystagmus were frequent in patients with pale optic nerve. Our findings might suggest the need for earlier ophthalmologic referral for CFCS patients due to high risk of amblyopia, especially those expressing BRAF mutations.

Skeletal defects and bone metabolism in Noonan, Costello and cardio-facio-cutaneous syndromes

Noonan, Costello and Cardio-facio-cutaneous syndromes belong to a group of disorders named RASopathies due to their common pathogenetic origin that lies on the Ras/MAPK signaling pathway. Genetics has eased, at least in part, the distinction of these entities as they are presented with overlapping clinical features which, sometimes, become more pronounced with age. Distinctive face, cardiac and skeletal defects are among the primary abnormalities seen in these patients. Skeletal dysmorphisms range from mild to severe and may include anterior chest wall anomalies, scoliosis, kyphosis, short stature, hand anomalies, muscle weakness, osteopenia or/and osteoporosis. Patients usually have increased serum concentrations of bone resorption markers, while markers of bone formation are within normal range. The causative molecular defects encompass the members of the Ras/MAPK/ERK pathway and the adjacent cascades, important for the maintenance of normal bone homeostasis. It has been suggested that modulation of the expression of specific molecules involved in the processes of bone remodeling may affect the osteogenic fate decision, potentially, bringing out new pharmaceutical targets. Currently, the laboratory imprint of bone metabolism on the clinical picture of the affected individuals is not clear, maybe due to the rarity of these syndromes, the small number of the recruited patients and the methods used for the description of their clinical and biochemical profiles.

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.

Bone health in RASopathies

The RASopathies are a group of disorders due to pathogenic variants in genes involved in the Ras/MAPK pathway, many of which have overlapping clinical features (e.g., neurofibromatosis type 1, Costello syndrome, cardiofaciocutaneous syndrome and Noonan syndrome) including musculoskeletal manifestations. Osteopenia and osteoporosis are reported in many of the RASopathies suggesting a shared pathogenesis. Even though osteopenia and osteoporosis are often detected and fractures have been reported, the clinical impact of bone mineralization defects on the skeleton of the various syndromes is poorly understood. Further knowledge of the role of the Ras/MAPK pathway on the bone cellular function, and more detailed musculoskeletal phenotyping will be critical in helping to develop therapies to improve bone health in the RASopathies.

Multidisciplinary Management of Costello Syndrome: Current Perspectives

Costello syndrome (CS) is a rare neurodevelopmental disorder caused by germline mutations in HRAS. It belongs among the RASopathies, a group of syndromes characterized by alterations in components of the RAS/MAPK signaling pathway and sharing overlapping phenotypes. Its typical features include a distinctive facial appearance, growth delay, intellectual disability, ectodermal, cardiac, and musculoskeletal abnormalities, and cancer predisposition. Due to the several comorbidities having a strong impact on the quality of life, a multidisciplinary team is essential in the management of such a condition from infancy to adult age, to promptly address any detected issue and to develop appropriate personalized follow-up protocols and treatment strategies. With the present paper we aim to highlight the core and ancillary medical disciplines involved in managing the health challenges characterizing CS from pediatric to adult age, according to literature and to our large clinical experience.

Case report: The cardio-facio-cutaneous syndrome due to a novel germline mutation in MAP2K1: A multifaceted disease with immunodeficiency and short stature

Cardio-facio-cutaneous syndrome (CFCS) belongs to the group of RASopathies, clinical disorders defined by disruptions in the RAS/MAPK signaling pathway. It is caused by heterozygous gain-of-function germline mutations in genes encoding protein kinases: BRAF, MAP2K1 (MEK1), MAP2K2 (MEK2), and in the GTPase-encoding gene KRAS. CFCS is characterized by craniofacial dysmorphic features, congenital heart defects, severe malnutrition, proportionate short stature, anomalies within the structure of skin and hair, and psychomotor disability. The pathophysiology of growth impairment is multifactorial with feeding difficulties, growth hormone deficiency, and insensitivity. Immunodeficiency has not been hitherto reported as an integral part of CFCS yet an increased activation of the RAS/MAPK signaling pathway may contribute to explaining the causal relationship between RASopathy and the dysfunctions within the B and T lymph cell compartments resulting in a deficiency in T cell costimulation and B cell maturation with impaired class switch recombination, somatic hypermutation, and high-affinity antibody production. We report on a boy born prematurely at 32 WGA, with the perinatal period complicated by pneumonia, respiratory distress syndrome, and valvular pulmonary stenosis. The boy suffered from recurrent pneumonia, obstructive bronchitis, sepsis, urinary tract infection, and recurrent fevers. He presented with severe hypotrophy, psychomotor disability, short stature, craniofacial dysmorphism, dental hypoplasia, sparse hair, and cryptorchidism. Whole genome sequencing showed a novel heterozygous pathogenic germline missense variant: c.364A > G; p.Asn122Asp in the MAP2K1 gene, supporting the diagnosis of CFCS. The immunological workup revealed hypogammaglobulinemia, IgG subclass, and specific antibody deficiency accompanied by decreased numbers of T helper cells and naive and memory B cells. Replacement immunoglobulin therapy with timely antibiotic prophylaxis were instituted. At the age of six years, growth hormone deficiency was diagnosed and the rGH therapy was started. The ever-increasing progress in genetic studies contributes to establishing the definitive CFCS diagnosis and sheds the light on the interrelated genotype-phenotype heterogeneity of RASopathies. Herein, we add new phenotypic features of predominating humoral immunodeficiency to the symptomatology of CFCS with a novel mutation in MAP2K1. While CFCS is a multifaceted disease, increased pediatricians' awareness is needed to prevent the delay in diagnostics and therapeutic interventions.

Bone tissue homeostasis and risk of fractures in Costello syndrome: A 4-year follow-up study

Costello syndrome (CS) is a neurodevelopmental disorder with a distinctive musculoskeletal phenotype and reduced bone mineral density (BMD) caused by activating de novo mutations in the HRAS gene. Herein, we report the results of a prospective study evaluating the efficacy of a 4-year vitamin D supplementation on BMD and bone health. A cohort of 16 individuals ranging from pediatric to adult age with molecularly confirmed CS underwent dosages of bone metabolism biomarkers (serum/urine) and dual-energy X-ray absorptiometry (DXA) scans to assess bone and body composition parameters. Results were compared to age-matched control groups. At baseline evaluation, BMD was significantly reduced (p ≤ 0.05) compared to controls, as were the 25(OH)vitD levels. Following the 4-year time interval, despite vitamin D supplementation therapy at adequate dosages, no significant improvement in BMD was observed. The present data confirm that 25(OH)vitD and BMD parameters are reduced in CS, and vitamin D supplementation is not sufficient to restore proper BMD values. Based on this evidence, routine monitoring of bone homeostasis to prevent bone deterioration and possible fractures in adult patients with CS is highly recommended.

Characterization of bone homeostasis in individuals affected by cardio-facio-cutaneous syndrome

Cardio-facio-cutaneous syndrome (CFCS) is a rare disorder characterized by distinctive craniofacial appearance, cardiac, neurologic, cutaneous, and musculoskeletal abnormalities. It is due to heterozygous mutations in BRAF, MAP2K1, MAP2K2, and KRAS genes, belonging to the RAS/MAPK pathway. The role of RAS signaling in bone homeostasis is highly recognized, but data on bone mineral density (BMD) in CFCS are lacking. In the present study we evaluated bone parameters, serum and urinary bone metabolites in 14 individuals with a molecularly confirmed diagnosis of CFCS. Bone assessment was performed through dual X-ray absorptiometry (DXA); height-adjusted results were compared to age- and sex-matched controls. Blood and urinary bone metabolites were also analyzed and compared to the reference range. Despite vitamin D supplementation and almost normal bone metabolism biomarkers, CFCS patients showed significantly decreased absolute values of DXA-assessed subtotal and lumbar BMD (p ≤ 0.05), compared to controls. BMD z-scores and t-scores (respectively collected for children and adults) were below the reference range in CFCS, while normal in healthy controls. These findings confirmed a reduction in BMD in CFCS and highlighted the importance of monitoring bone health in these affected individuals.

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.

Musculo-skeletal phenotype of Costello syndrome and cardio-facio-cutaneous syndrome: insights on the functional assessment status

Background

Costello syndrome (CS) and cardio-facio-cutaneous syndrome (CFCS) belong to the RASopathies, a group of neurodevelopmental disorders with skeletal anomalies. Due to their rarity, the characterization of the musculo-skeletal phenotype in both disorders has been poorly characterized.

Patients and methods

Herein we reported data on orthopedic findings and functional status of a large sample of CS and CFCS patients. Thirty-four patients (CS = 17 and CFCS = 17) were recruited. Functional and disability evaluations were performed by assessing the 6-min walking test (6MWT) and Pediatric Outcomes Data Collection Instrument (PODCI). Genotype/phenotype correlation was also provided.

Results

Orthopedic manifestations are highly prevalent in CS and CFCS and overlap in the two disorders. Overall, patients with CS harboring the recurrent HRAS Gly12Ser substitution show a more severe skeletal phenotype compared to patients carrying the Gly12Ala and Gly13Cys variants. Among CFCS patients, those with the MAP2K1/2 variant show different skeletal characteristics compared to BRAF variants, with a higher prevalence of orthopedic abnormalities. Functional assessment showed that patients with CS and CFCS reached lower values compared to the general population, with CFCS patients displaying the lowest scores.

Conclusions

Orthopedic manifestations appear universal features of CS and CFCS and they can evolve across patients’ life. Longitudinal assessment of disability status by using 6MWT and PODCI could be useful to evaluate the functional impact of orthopedic manifestations on patients’ outcome and help planning a tailored treatment of these comorbidities.

Treatment of Dystonia Using Trihexyphenidyl in Costello Syndrome

Costello syndrome (CS), a rare syndrome with multisystemic involvement inherited as a dominant trait, is characterized by developmental delay, coarse facial appearance, cardiac defects including hypertrophic cardiomyopathy, skin abnormalities, brain complications, and a predisposition to certain malignancies. The musculoskeletal system is particularly affected in CS, with peculiar orthopedic anomalies that impact posture and gait. Dystonia has been recently documented to contribute to abnormal postures and musculoskeletal anomalies characterizing CS, suggesting the possible use of pharmacological treatments to treat these complications. We report the case of a child affected by CS displaying a particularly severe musculoskeletal involvement with dystonic posture especially in the arms and legs. The Movement Disorder-Childhood Rating Scale (MD-CRS) and a gait analysis were used to assess clinical patterns of hyperkinetic movement disorder and dystonia. The child was further treated with trihexyphenidyl for six months with a final dosage of 14 mg. MD-CRS and gait analysis assessments provided evidence for a significant improvement of posture and the related musculoskeletal problems with no side effects. Our preliminary study report provides first evidence that pharmacological anti-dystonia treatment significantly improves movement and posture disorders in patients with CS. Further studies enrolling larger cohorts of patients should be performed to validate these preliminary observations.

A comparison of the functional health of children with Costello syndrome in 1999 and in 2015

Costello Syndrome is a rare congenital condition characterized by failure-to-thrive, cardiac abnormalities, distinctive facial features, predisposition to malignant tumors, and developmental delay. In 1999, we analyzed the functional health in a cohort of 18 patients. Since then, a mutation in the HRAS gene has been found to be causative, medical management has been refined, and the level of awareness has increased. The purpose of this study is to compare the functional health outcomes from the 1999 cohort with data prospectively collected from a comparable cohort in 2015. The Pediatric Outcome Data Collection Instrument (PODCI) was administered to parents of children with Costello syndrome during the 2015 International Costello Syndrome Conference. The same instrument and setting were used in the 1999 study. We compared functional health scores from the two groups. A total of 21 participants were included in the 2015 cohort; 15 females (71%) and 6 males (29%). Average age was 5.8 years (range 2-16). When comparing functional health outcomes, we found that the 2015 cohort scored slightly higher in Upper Extremity and Physical Function (57 vs. 54) and Comfort scales (86 vs. 82). However, there was no significant difference in any of the PODCI scales between the two groups. When compared with normative scores, both groups scored significantly lower in every scale except for happiness (p = 0.2952). Despite recent advancements, functional health outcomes in 2015 were similar to those measured in a different cohort in 1999.

Age-related differences in prevalence of autism spectrum disorder symptoms in children and adolescents with Costello syndrome

Dysregulation of the mitogen activated protein kinase (MAPK) pathway in Costello syndrome (CS) may contribute to increased risk for autism-spectrum disorder (ASD). We examined prevalence of ASD symptoms in 14 individuals (six females) age 1-18 years with molecularly confirmed CS. Caregivers completed the Modified Checklist for Autism in Toddlers (M-CHAT) for ages 0-4 years (n = 7), and the Social Communication Questionnaire (SCQ) for ages 4 and older (n = 7). Age was associated with meeting ASD criteria: 5/7 (71.4%) younger children met the ASD cut-off on the MCHAT, compared to 0/7 older children on the SCQ. The following medical and developmental factors were strongly associated with ASD criteria on the M-CHAT: having a gastrostomy tube at time of assessment, not eating solid food, not walking, and not being toilet trained. Two children who met stricter ASD criteria had significantly lower adaptive functioning and were physically much more impaired. Among older participants, SCQ subscale scores in communication, socialization, and repetitive behavior domains were comparable to the typically-developing normative sample. ASD symptoms were highly elevated in younger CS individuals. Older children did not differ from typically developing samples in prevalence of ASD symptoms. CS individuals may appear to fall on the autism spectrum in early childhood due to severe feeding and orthopedic problems that improve by age four, suggesting many of these children may eventually emerge out of an ASD presentation.

Behavioral functioning in cardiofaciocutaneous syndrome: Risk factors and impact on parenting experience

The present study is an investigation of behavioral functioning in children with cardiofaciocutaneous syndrome (CFC). CFC is a rare single-gene disorder associated with cardiac disease, characteristic skin and facial features, intellectual disability, and neurological complications such as seizures and structural brain anomalies. Emotional and behavioral features of CFC have not been systematically investigated. We aimed to identify key variables that contribute to psychopathology during childhood and adolescence, and to examine the impact of challenging behaviors on the caregiving experience. Parents of 34 children and adolescents with CFC completed standardized broadband measures of child emotional and behavioral functioning, as well as measures of sensory modulation, functional communication, and caregiver stress. Results indicate that children with CFC syndrome are at heightened risk for psychopathology, with attention problems, social difficulties, and unusual behaviors (e.g., obsessive thoughts, strange behaviors, repetitive acts) found to be especially prevalent. Behavioral challenges in children with CFC syndrome were significantly associated with a history of obstetric complications and with problems modulating sensory information. With regard to the impact of child neurocognitive and behavioral issues on the caregiving experience, parent self-reported stress was significantly higher among parents of children who engaged in more problem behaviors, and lower among parents whose children could communicate effectively with others. Results of this study suggest avenues to help families cope with CFC-related stressors and enhance overall functioning. In particular, this study highlights the need for educational and treatment interventions aimed at addressing sensory needs, increasing functional communication, and identifying and managing challenging behaviors. © 2016 Wiley Periodicals, Inc.