Les RASopathies avec phénotype Noonan associent le syndrome de Noonan (SN), le syndrome cardio-facio-cutané (SCFC) et le syndrome de Costello (SC). Leurs manifestations dermatologiques restent peu étudiées.Objectifs Colliger les différentes manifestations dermatologiques des SN, SCFC et SC afin d’établir leur nature et leur prévalence, et définir d’éventuelles corrélations phénotype/génotype au sein de chacune de ces affections.Méthodes Les patients atteints d’un SN, SCFC et SC confirmé sur le plan moléculaire par la présence d’une mutation germinale pathogène étaient inclus dans une étude menée durant 5 ans dans les départements de Génétique, Dermatologie et Pédiatrie des CHU de Bordeaux, Marseille, Montpellier, Nancy, Nantes, Paris AP-HP (Hôpital Robert-Debré et Hôpital Necker-Enfants Malades), Rennes, Saint-Pierre (La Réunion) et Toulouse.Résultats Cent quatre-vingt-quatorze patients atteints de SN, SCFC et SC étaient inclus. Cent-vingt et un patients atteints de SN étaient inclus. La tendance aux hématomes était la manifestation la plus fréquente au cours du SN-PTPN11 (53.8%). Les ML et les tâches café-au-lait atypiques (≥3) étaient observés respectivement dans 94% et 80% des SNML liés à des mutations spécifiques de PTPN11. Des formes atypiques de SNML étaient associées au SN-RAF1 et SN-NRAS. En analyse univariée, les patients sans mutation PTPN11 présentaient (i) un risque de troubles de la kératinisation augmenté (P=0.001), dont la kératose pilaire (KP) (P=0.005), l’ulerythema ophryogenes (UO) (P=0.0001) et la kératodermie palmoplantaire (KPP) (P=0.06), et (ii) un risque augmenté d’alopécie du scalp (P=0.035) et des cils (P=0.06) par rapport aux patients sans mutation PTPN11.Quarante-cinq patients atteints de SCFC étaient inclus, parmi lesquels 77,8% avec mutation BRAF. Les anomalies pilaires étaient constantes, incluant une alopécie du scalp et des sourcils et des cheveux frisés ou bouclés respectivement dans 73% et 69% des cas. Une KP, un UO, une KPP et de multiples naevi (MN >50) étaient observés respectivement dans 82%, 44%, 27% et 29% des cas. L’alopécie des sourcils, l’association UO et KPP, la KP diffuse, et les MN constituaient des signes pertinents de différenciation du SCFC avec le SN et le SC. L’acitrétine orale permettait de traiter avec succès la KPP, tandis que le traitement de l’UO par sirolimus à 1% en topique échouait. Aucune corrélation phénotype-génotype n’était notée.Vingt-et-un patients atteints de SC étaient inclus, parmi lesquels 60% avec la mutation p.G12S-HRAS. Les anomalies pilaires étaient constantes, comprenant des cheveux frisés ou bouclés et une alopécie du scalp respectivement dans 70% and 60% des cas. Un acanthosis nigricans, des papillomes, une KPP, et une cutis laxa acrale étaient notés respectivement dans 65%, 65%, 55% et 80% des cas. Des papules linéaires à disposition pavimenteuse de la lèvre supérieure étaient présentes dans 55% des cas, tandis que l’alopécie des sourcils ou le lymphoedème n’étaient pas observés. Aucune corrélation phénotype-génotype n’était notée. Un patient avec SC atypique avec mutation c187_207dup21/p.Glu63_Asp69dup-HRAS présentait un phénotype cutané distinct associant des MN, un lymphoedème et des manifestations dermatologiques de SC, évoquant une nouvelle forme phénotypique de chevauchement entre un SC et un SN et/ou un SCFC.Conclusion La connaissance précise des manifestations dermatologiques des RASopathies et l’identification de thérapeutiques permet une optimisation de leur prise en charge. / Background Data on dermatological manifestations of RASopathies with Noonan phenotype including Noonan syndrome (NS), cardiofaciocutaneous syndrome (CFCS) and Costello syndrome (CS) remain heterogeneous and based on little dermatological expertise.Objectives To describe the dermatological manifestations of NS, CFCS and CS compare them with the literature findings, and test for dermatological phenotype-genotype correlations with or without the presence of PTPN11, BRAF and pG12S-HRAS mutations respectively for NS, CFCS and CS.Methods We performed a large, 5-year, prospective, multicentric, collaborative dermatological and genetic study.Results A total of 194 patients with NS, CFC and CS were included. One hundred and twenty-nine patients with NS were enrolled, including 65 with PTPN11-NS, 34 with PTPN11-NS with multiple lentigines (NSML), and 30 without PTPN11-NS. Easy bruising was the most frequent dermatological finding in PTPN11-NS, present in 53.8%. Multiple lentigines and café-au-lait macules (≥3) were present in, respectively, 94% and 80% of NSML linked to specific mutations of PTPN11. Atypical forms of NSML could be associated with NS with RAF1 or NRAS mutations. In univariate analysis, patients without a PTPN11 mutation showed (i) a significantly higher frequency of keratinization disorders (P=0.001), including keratosis pilaris (P=0.005), ulerythema ophryogenes (P=0.0001) and palmar and/or plantar hyperkeratosis (P=0.06, trend association), and (ii) a significantly higher frequency of scarce scalp hair (P=0.035) and scarce or absent eyelashes (P=0.06, trend association) than those with PTPN11 mutations. Forty-five patients with CFCS were enrolled with mutations in BRAFin 77.8%. Hair abnormalities were ubiquitous, including scarcity or absence of eyebrows and wavy or curly hair respectively in 73% and 69%. Keratosis pilaris (KP), ulerythema ophryogenes (UO), palmo-plantar hyperkeratosis (PPHK), and multiple melanocytic naevi (MMN; MN >50) were noted respectively in 82%, 44%, 27% and 29%. Scarcity or absence of eyebrows, association of UO and PPHK, diffuse KP, and MMN best differentiated CFCS from NS and CS. Oral acitretin may be highly beneficial for therapeutic management of PPHK, whereas treatment of UO by topical 1% sirolimus failed. No significant dermatological phenotype-genotype correlation was determined. Twenty-one patients with CS were enrolled with p.G12S mutation of HRAS identified respectively in 60%. Hair abnormalities were ubiquitous, including wavy or curly hair and scalp alopecia respectively in 70% and 60%. Acanthosis nigricans with pachydermatoglyphia, papillomas with periorificial location, PPHK, and acral cutis laxa were noted respectively in 65%, 65%, 55% and 80%. Cobblestone papillomatous linear papules of the upper lip was present in 55%, while scarcity of eyebrows and lymphedema were almost absent. No significant dermatological phenotype-genotype correlation was determined. One patient with CS with c187_207dup21/p.Glu63_Asp69dup mutation of HRAS had a new distinct cutaneous phenotype including MMN and severe lymphedema similar to NS and/or CFCS findings.Conclusions A thorough knowledge of RASopathies skin manifestations would help in making a positive diagnosis.

Thèse d'exercice : Médecine. Génétique médicale : Paris 12 : 2006. / Titre provenant de l'écran-titre. Bibliogr. f. 45-51.

Reproduction de : Thèse d'exercice : Médecine. Génétique médicale : Paris 12 : 2008. / Titre provenant de l'écran-titre. Bibliogr. f. 70-76.

No description available.

In addition to their role in hemostasis, platelets appear to contribute to vascular inflammatory diseases. Platelets achieve this through the secretion of various prothrombotic and pro-inflammatory molecules. Platelet secretion is mediated by integral membrane proteins called Soluble NSF Attachment protein REceptors (SNAREs). SNAREs come from both granule/vesicle membranes (v-SNAREs) and target membranes (t-SNAREs) to form a trans-bilayer complex that promotes membrane fusion and subsequent granule cargo release. The work described in this dissertation dissects various, yet related aspects of platelet secretion in both physiological relevant and pathological circumstances. Atherosclerosis is a leading cause of death in the westernized countries and a major contributor to heart attacks and strokes. Given the potential involvement of platelets in atherosclerosis and previous work from our laboratory showing that VAMP-8 is the primary v-SNARE for platelet secretion, one part of this dissertation focuses on the role of VAMP-8- mediated secretion in atherosclerosis. The data showed that the deletion of VAMP-8 in the ApoE-/- null model of chronic atherosclerosis attenuated plaque development compared to the wild type littermates. Aged (50 week) VAMP-8-/-/ApoE-/- mice showed a reduction in lesion size compared to ApoE-/- controls, as measured by Oil Red-O staining of the plaques in the aortic sinus and by en face analysis of plaques in the aortic arch. These data show that the loss of VAMP-8 attenuates the development of atherosclerotic plaques and suggest that platelet secretion contributes to atherosclerosis. Considering the vital role of platelet secretion in both physiological and pathological conditions, it is essential to understand how it is regulated. SNARE proteins are controlled by a range of regulatory molecules that affect where, when, and with whom they form trans-bilayer complexes for membrane fusion. One family of such regulators is the Munc18 family: platelets contain three (Munc18a-c). The second part of this dissertation focuses on the role of Munc18b/STXBP2. Mutations in the Munc18b/STXBP2 gene underlie Familial Hemophagocytic Lymphohistocytosis type 5 (FHL5), which is a life- threatening disease caused by dysregulation of the immune system. Platelets from two biallelic FHL5 patients had almost undetectable levels of Munc18b/STXBP2 levels; the levels of Munc18a increased slightly and Munc18c levels were unaffected. Syntaxin 11 levels were affected but the levels of other secretory machinery proteins were normal. Platelet secretion from dense and alpha granule in two biallelic patients and the one heterozygous patient was decreased. The release of serotonin from dense granules, and platelet factor 4 (PF4) from alpha granules was profoundly affected in the biallelic patients and partially affected in the heterozygote heterozygous patient. Lysosome release was affected only from the platelets of the biallelic patients. These data indicate that Munc18b plays a key role in platelet secretion. Ras is the prototypical member of a family of low molecular weight, GTP-binding proteins. It affects various cellular functions by cycling between an active, guanine triphosphate (GTP) and an inactive guanine diphosphate (GDP) -bound state. Little is known about the role of Ras activation in platelets. The third part of this dissertation focuses on what could be learned about Ras’ role by analyzing platelets from patients with Noonan Syndrome. Specific mutations in the genes encoding elements of Ras signaling pathways are associated with Noonan Syndrome. Platelets from Noonan Syndrome patients with a mutation in kRas (F156V) were analyzed and shown to have a defect in aggregation in response to low levels of agonist. These data suggest that Ras may play a functionally relevant role in platelet activation. In summary, the experiments presented in investigations of this dissertation support a role for platelet secretion in several pathological conditions and suggest that platelet secretion assays may serve as useful as diagnostic tools for some genetic diseases. In addition, these studies elucidate the importance of understanding the regulation of platelet exocytosis, to drive the development of new antithrombotic therapeutics.

A Síndrome de Noonan (SN) é caracterizada por baixa estatura proporcionada de início pós-natal, dismorfismos faciais, cardiopatia congênita e deformidade torácica. A frequência da SN é estimada entre 1:1000 e 1:2500 nascidos vivos, com distribuição semelhante em ambos os sexos. A herança é autossômica dominante com penetrância completa, porém a maioria dos casos é esporádica. Até o momento, mutações em genes da via RAS-MAPK (PTPN11, KRAS, SOS1, RAF1, MEK1, NRAS e SHOC2) foram identificadas em aproximadamente 70% dos pacientes. Uma das principais características fenotípicas da SN é a baixa estatura pós-natal, embora o mecanismo fisiopatológico do déficit de crescimento nesta síndrome ainda não esteja totalmente esclarecido. Estudos que avaliaram o padrão de crescimento linear em crianças com SN foram realizados anteriormente ao conhecimento do diagnóstico molecular dessa síndrome. No presente estudo, avaliamos a frequência de mutação nos genes PTPN11, SOS1, RAF1 e KRAS em 152 pacientes com SN e o padrão de crescimento linear (altura) e ponderal [índice de massa corpórea (IMC)] dos pacientes com mutação identificada. No total, mutações nos genes relacionados foram encontradas em 99 pacientes (65%) do nosso estudo, com predominância do gene PTPN11 (47%), seguido do SOS1 (9%), RAF1 (7%) e KRAS (3%). Foram construídas curvas específicas para SN de Altura e IMC para idade e sexo utilizando o método LMS. Os pacientes com SN apresentaram crescimento pré-natal preservado, porém o comprometimento do crescimento pós-natal foi observado desde o primeiro ano de vida, atingindo uma altura final de -2,5 e -2,2 desvios-padrão da média para população brasileira em homens e mulheres, respectivamente. O prejuízo da altura foi maior nos pacientes com mutação no gene RAF1 em comparação com os genes PTPN11 e SOS1. O IMC dos pacientes com SN apresentou queda de 1 desvio-padrão em relação à média da população brasileira normal. O comprometimento do IMC foi menor nos pacientes carreadores de mutação no RAF1. Pacientes com mutação nos genes PTPN11 e SOS1 apresentaram maior frequência de estenose de valva pulmonar, enquanto a miocardiopatia hipertrófica foi mais frequente nos pacientes com mutação no gene RAF1. A variabilidade fenotípica observada nos pacientes com mutação no PTPN11 não pode ser explicada pelo grau que estas mutações influenciam a atividade tirosina fosfatase da SHP-2 nem pela presença de polimorfismos no gene KRAS. Com a análise dos éxons 3, 8 e 13 do PTPN11, seguido dos éxons 6 e 10 do SOS1 e éxon 7 do RAF1 identificamos 86% dos pacientes carreadores de mutações nos genes relacionados, propondo uma forma mais eficiente de avaliação molecular na SN. Acreditamos que a variabilidade fenotípica presente nessa síndrome esteja diretamente ligada aos diferentes papéis exercidos pelas proteínas que participam da via RAS/MAPK. Entretanto, mais estudos em relação à via RAS/MAPK serão necessários para esclarecer as questões relacionadas ao crescimento e outras características fenotípicas da SN / Noonan Syndrome (NS) is characterized by distinctive facial features, short stature and congenital heart defects. The estimated prevalence is 1:1000 to 1:2500 live births, affecting equally both sexes. It is an autosomal dominant disorder with complete penetrance, but most cases are sporadic. To date, mutations in the RAS/MAPK pathway genes (PTPN11, KRAS, SOS1, RAF1, MEK1, NRAS and SHOC2) were identified in approximately 70% of patients. One of the cardinal signs of NS is proportional postnatal short stature although the physiopathological mechanism of growth impairment remains unclear. The current knowledge about the natural history of growth associated with NS was described before molecular diagnosis era. In this study, we performed PTPN11, SOS1, RAF1, and KRAS mutation analysis in a cohort of 152 NS patients and studied the natural linear (height) and ponderal growth [body mass index (BMI)] of NS patients with related mutations. Mutations in NS-causative genes were found in 99 patients (65%) of our cohort. The most common mutated gene was PTPN11 (47%), followed by SOS1 (9%), RAF1 (7%) and KRAS (3%). Sex-specific percentile curves for height and BMI were constructed using the LMS method. NS patients had birth weight and length within normal ranges but the postnatal growth impairment was observed during the first year of life, reaching a final height of -2.3 and -2.2 standard deviations from the mean for Brazilian healthy men and women, respectively. Postnatal growth impairment was higher in RAF1 mutation patients than in patients with SOS1 and PTPN11 mutations. BMI values in NS patients were lower in comparison with normal Brazilian population. BMI values were higher in patients with RAF1 mutations than in patients with other genotypes. Patients with mutations in PTPN11 and SOS1 genes were more likely to have pulmonary valve stenosis, whereas hypertrophic cardiomyopathy was more common in patients with mutations in the gene RAF1. The intensity of constitutive tyrosine phosphatase activity of SHP-2 due to PTPN11 mutations, as well as the presence of polymorphisms in KRAS gene did not influence the phenotype of NS patients with mutation in PTPN11 gene. Analysis of exons 3, 8 and 13 of PTPN11 gene, followed by exons 6 and 10 of SOS1 gene and exon 7of RAF1 gene identified 86% of patients harboring mutations in related genes, suggesting a more efficient evaluation of NS molecular diagnosis. We believe that the phenotypic variability in this syndrome is directly linked to the different roles played by proteins that participate in RAS/MAPK pathway. However, further studies in RAS/MAPK pathway are needed to clarify issues related to growth and other phenotypic characteristics of SN

A Síndrome de Noonan (SN) é caracterizada por baixa estatura proporcionada de início pós-natal, dismorfismos faciais, cardiopatia congênita e deformidade torácica. A frequência da SN é estimada entre 1:1000 e 1:2500 nascidos vivos, com distribuição semelhante em ambos os sexos. A herança é autossômica dominante com penetrância completa, porém a maioria dos casos é esporádica. Até o momento, mutações em genes da via RAS-MAPK (PTPN11, KRAS, SOS1, RAF1, MEK1, NRAS e SHOC2) foram identificadas em aproximadamente 70% dos pacientes. Uma das principais características fenotípicas da SN é a baixa estatura pós-natal, embora o mecanismo fisiopatológico do déficit de crescimento nesta síndrome ainda não esteja totalmente esclarecido. Estudos que avaliaram o padrão de crescimento linear em crianças com SN foram realizados anteriormente ao conhecimento do diagnóstico molecular dessa síndrome. No presente estudo, avaliamos a frequência de mutação nos genes PTPN11, SOS1, RAF1 e KRAS em 152 pacientes com SN e o padrão de crescimento linear (altura) e ponderal [índice de massa corpórea (IMC)] dos pacientes com mutação identificada. No total, mutações nos genes relacionados foram encontradas em 99 pacientes (65%) do nosso estudo, com predominância do gene PTPN11 (47%), seguido do SOS1 (9%), RAF1 (7%) e KRAS (3%). Foram construídas curvas específicas para SN de Altura e IMC para idade e sexo utilizando o método LMS. Os pacientes com SN apresentaram crescimento pré-natal preservado, porém o comprometimento do crescimento pós-natal foi observado desde o primeiro ano de vida, atingindo uma altura final de -2,5 e -2,2 desvios-padrão da média para população brasileira em homens e mulheres, respectivamente. O prejuízo da altura foi maior nos pacientes com mutação no gene RAF1 em comparação com os genes PTPN11 e SOS1. O IMC dos pacientes com SN apresentou queda de 1 desvio-padrão em relação à média da população brasileira normal. O comprometimento do IMC foi menor nos pacientes carreadores de mutação no RAF1. Pacientes com mutação nos genes PTPN11 e SOS1 apresentaram maior frequência de estenose de valva pulmonar, enquanto a miocardiopatia hipertrófica foi mais frequente nos pacientes com mutação no gene RAF1. A variabilidade fenotípica observada nos pacientes com mutação no PTPN11 não pode ser explicada pelo grau que estas mutações influenciam a atividade tirosina fosfatase da SHP-2 nem pela presença de polimorfismos no gene KRAS. Com a análise dos éxons 3, 8 e 13 do PTPN11, seguido dos éxons 6 e 10 do SOS1 e éxon 7 do RAF1 identificamos 86% dos pacientes carreadores de mutações nos genes relacionados, propondo uma forma mais eficiente de avaliação molecular na SN. Acreditamos que a variabilidade fenotípica presente nessa síndrome esteja diretamente ligada aos diferentes papéis exercidos pelas proteínas que participam da via RAS/MAPK. Entretanto, mais estudos em relação à via RAS/MAPK serão necessários para esclarecer as questões relacionadas ao crescimento e outras características fenotípicas da SN / Noonan Syndrome (NS) is characterized by distinctive facial features, short stature and congenital heart defects. The estimated prevalence is 1:1000 to 1:2500 live births, affecting equally both sexes. It is an autosomal dominant disorder with complete penetrance, but most cases are sporadic. To date, mutations in the RAS/MAPK pathway genes (PTPN11, KRAS, SOS1, RAF1, MEK1, NRAS and SHOC2) were identified in approximately 70% of patients. One of the cardinal signs of NS is proportional postnatal short stature although the physiopathological mechanism of growth impairment remains unclear. The current knowledge about the natural history of growth associated with NS was described before molecular diagnosis era. In this study, we performed PTPN11, SOS1, RAF1, and KRAS mutation analysis in a cohort of 152 NS patients and studied the natural linear (height) and ponderal growth [body mass index (BMI)] of NS patients with related mutations. Mutations in NS-causative genes were found in 99 patients (65%) of our cohort. The most common mutated gene was PTPN11 (47%), followed by SOS1 (9%), RAF1 (7%) and KRAS (3%). Sex-specific percentile curves for height and BMI were constructed using the LMS method. NS patients had birth weight and length within normal ranges but the postnatal growth impairment was observed during the first year of life, reaching a final height of -2.3 and -2.2 standard deviations from the mean for Brazilian healthy men and women, respectively. Postnatal growth impairment was higher in RAF1 mutation patients than in patients with SOS1 and PTPN11 mutations. BMI values in NS patients were lower in comparison with normal Brazilian population. BMI values were higher in patients with RAF1 mutations than in patients with other genotypes. Patients with mutations in PTPN11 and SOS1 genes were more likely to have pulmonary valve stenosis, whereas hypertrophic cardiomyopathy was more common in patients with mutations in the gene RAF1. The intensity of constitutive tyrosine phosphatase activity of SHP-2 due to PTPN11 mutations, as well as the presence of polymorphisms in KRAS gene did not influence the phenotype of NS patients with mutation in PTPN11 gene. Analysis of exons 3, 8 and 13 of PTPN11 gene, followed by exons 6 and 10 of SOS1 gene and exon 7of RAF1 gene identified 86% of patients harboring mutations in related genes, suggesting a more efficient evaluation of NS molecular diagnosis. We believe that the phenotypic variability in this syndrome is directly linked to the different roles played by proteins that participate in RAS/MAPK pathway. However, further studies in RAS/MAPK pathway are needed to clarify issues related to growth and other phenotypic characteristics of SN

INTRODUÇÃO: as RASopatias, que englobam a síndrome de Noonan e as síndromes relacionadas à síndrome de Noonan (Noonan-like), são doenças monogênicas de herança autossômica dominante causadas por mutações em genes pertencentes a mesma via de sinalização (RAS-MAPK). Caracterizam-se por um envolvimento multissistêmico, no qual a baixa estatura é um sinal cardinal. Os aspectos nutricionais são mais estudados nas síndromes relacionadas à síndrome de Noonan, nas quais uma dificuldade alimentar nos primeiros meses de vida é mais frequente e acentuada, requerendo uma intervenção terapêutica. OBJETIVOS: avaliar o estado nutricional de indivíduos com RASopatias, o consumo de energia e macronutrientes de acordo com a idade e gênero, comparar os dados antropométricos e o consumo alimentar com os dados populacionais e estabelecer uma associação entre o genótipo e o fenótipo dos indivíduos. MÉTODOS: o estado nutricional de 62 indivíduos com Rasopatias, confirmado por estudo molecular, com mediana de idade de 12 anos, foi avaliado a partir da realização de medidas antropométricas (peso, estatura, circunferência do braço e prega tricipital), da análise do consumo alimentar habitual e do nível de atividade física. RESULTADOS: Observou-se um déficit de crescimento de origem pós-natal em 48% dos indivíduos e, na classificação pelo índice de massa corpórea, aproximadamente 80% deles foram classificados como eutróficos ou com baixo peso/ magreza acentuada. Os parâmetros de composição corporal mostraram um comprometimento na circunferência muscular do braço e, nas classificações pela área gordurosa do braço e área muscular do braço, 43,5% apresentavam baixa reserva de gordura e 69% eram desnutridos ou abaixo da média, respectivamente. Ao associar o genótipo ao fenótipo dos indivíduos estudados, os genes SHOC2, RAF1 e KRAS eram os que apresentavam os valores médios mais baixos de estatura e os indivíduos com mutações no gene SHOC2, os menores valores de mediana de índice de massa corpórea Já os indivíduos com mutações no gene BRAF tiveram os maiores valores desta mediana. Houve uma diferença estatisticamente significante no escore-Z da dobra cutânea tricipital e na área gordurosa do braço entre BRAF e SHOC2 e no escore-Z da dobra cutânea tricipital entre RAF1 e SHOC2. O consumo energético e de macronutrientes dos indivíduos foi semelhante à referência de ingestão diária e ao da população brasileira e no nível de atividade física, 65,4% eram sedentários e irregularmente ativos. Encontrou-se somente um indivíduo com dificuldade importante na alimentação, necessitando de gastrostomia. CONCLUSÕES: A baixa estatura é frequente e mais pronunciada nos indivíduos com mutação nos genes SHOC2, RAF1 e KRAS. Diferindo da tendência da população mundial a apresentar uma alta prevalência de obesidade, a grande maioria dos indivíduos com RASopatias apresenta-se eutrófica ou com baixo peso/magreza. Na composição corpórea, há um acometimento do tecido muscular em todos os indivíduos estudados. A diminuição destas medidas não é explicada por uma baixa ingesta alimentar e nem por um aumento nas atividades físicas do grupo. É possível que os fatores genéticos, por um aumento da sinalização da via RAS-MAPK, confiram um perfil mais magro a estes indivíduos, por acometimento não apenas da gordura, mas especialmente da musculatura / INTRODUCTION: RASopathies that include Noonan syndrome and Noonan related disorders (Noonan-like) are monogenic conditions with autosomal dominant inheritance caused by mutations in genes belonging to the same signaling pathway (RAS-MAPK). They are characterized by a multisystemic involvement in which short stature is a cardinal feature. The nutritional aspects are more frequently described in Noonan related disorders, in which feeding difficulties in the first months of life are more frequent and severe, requiring therapeutic intervention. OBJECTIVES: To evaluate the nutritional aspects of individuals with RASopathies, the energy and macronutrients consumption, according to age and sex; to compare the anthropometric data and dietary intake with population references and to establish a genotype-phenotype correlation. METHODS: The nutritional status of 62 individuals with Rasopathies confirmed by DNA analysis, with a median age of 12 years was evaluated by performing anthropometric measurements (weight, height, arm circumference and triceps skinfold thickness), analysis of habitual food intake and physical activity level. RESULTS: There was growth deficiency of postnatal origin in 48% of subjects and in the classification by body mass index, approximately 80% of them were classified as eutrophic or underweight/thinness. The parameters of body composition showed a decreased upper arm muscle circumference and in the classification by the upper arm fat area and upper arm muscle area, 43.5% had low fat reserves and 69% were malnourished or below average, respectively. Genotype-phenotype correlation showed that individuals with mutations in SHOC2, RAF1 and KRAS were those presenting the lowest mean values of stature and individuals with mutations in SHOC2, the lower median values of bone mass index. On the other hand, individuals with mutations in the BRAF had the highest median values. There was a statistically significant difference of the triceps skinfold thickness and upper arm fat area between Z-scores between BRAF and SHOC2 and of the triceps skinfold thickness Z-score between RAF1 and SHOC2. The energy and macronutrient intake of the subjects were similar to the dietary intake reference and the Brazilian population and in the level of physical activity, 65.4% were sedentary and irregularly active. It was found only one individual with significant difficulty in feeding, requiring gastrostomy. CONCLUSIONS: Short stature is common and more pronounced in individuals with mutations in SHOC2, RAF1 and KRAS. Opposed to the trend of the world\'s population of an increased prevalence of obesity, the majority of individuals with RASopathies present as eutrophic or underweight/ thinness. In body composition, there is an involvement of muscle tissue in all studied subjects. The decrease of these measures in the group is explained neither by a lower food intake nor by an increase in physical activity. It is possible that genetic factors, leading to hyperactivation of the RAS/ MAPK signaling, confer a slimmer profile to these individuals, mostly by the muscle involvement and not only by a decrease in fat reserve

INTRODUÇÃO: as RASopatias, que englobam a síndrome de Noonan e as síndromes relacionadas à síndrome de Noonan (Noonan-like), são doenças monogênicas de herança autossômica dominante causadas por mutações em genes pertencentes a mesma via de sinalização (RAS-MAPK). Caracterizam-se por um envolvimento multissistêmico, no qual a baixa estatura é um sinal cardinal. Os aspectos nutricionais são mais estudados nas síndromes relacionadas à síndrome de Noonan, nas quais uma dificuldade alimentar nos primeiros meses de vida é mais frequente e acentuada, requerendo uma intervenção terapêutica. OBJETIVOS: avaliar o estado nutricional de indivíduos com RASopatias, o consumo de energia e macronutrientes de acordo com a idade e gênero, comparar os dados antropométricos e o consumo alimentar com os dados populacionais e estabelecer uma associação entre o genótipo e o fenótipo dos indivíduos. MÉTODOS: o estado nutricional de 62 indivíduos com Rasopatias, confirmado por estudo molecular, com mediana de idade de 12 anos, foi avaliado a partir da realização de medidas antropométricas (peso, estatura, circunferência do braço e prega tricipital), da análise do consumo alimentar habitual e do nível de atividade física. RESULTADOS: Observou-se um déficit de crescimento de origem pós-natal em 48% dos indivíduos e, na classificação pelo índice de massa corpórea, aproximadamente 80% deles foram classificados como eutróficos ou com baixo peso/ magreza acentuada. Os parâmetros de composição corporal mostraram um comprometimento na circunferência muscular do braço e, nas classificações pela área gordurosa do braço e área muscular do braço, 43,5% apresentavam baixa reserva de gordura e 69% eram desnutridos ou abaixo da média, respectivamente. Ao associar o genótipo ao fenótipo dos indivíduos estudados, os genes SHOC2, RAF1 e KRAS eram os que apresentavam os valores médios mais baixos de estatura e os indivíduos com mutações no gene SHOC2, os menores valores de mediana de índice de massa corpórea Já os indivíduos com mutações no gene BRAF tiveram os maiores valores desta mediana. Houve uma diferença estatisticamente significante no escore-Z da dobra cutânea tricipital e na área gordurosa do braço entre BRAF e SHOC2 e no escore-Z da dobra cutânea tricipital entre RAF1 e SHOC2. O consumo energético e de macronutrientes dos indivíduos foi semelhante à referência de ingestão diária e ao da população brasileira e no nível de atividade física, 65,4% eram sedentários e irregularmente ativos. Encontrou-se somente um indivíduo com dificuldade importante na alimentação, necessitando de gastrostomia. CONCLUSÕES: A baixa estatura é frequente e mais pronunciada nos indivíduos com mutação nos genes SHOC2, RAF1 e KRAS. Diferindo da tendência da população mundial a apresentar uma alta prevalência de obesidade, a grande maioria dos indivíduos com RASopatias apresenta-se eutrófica ou com baixo peso/magreza. Na composição corpórea, há um acometimento do tecido muscular em todos os indivíduos estudados. A diminuição destas medidas não é explicada por uma baixa ingesta alimentar e nem por um aumento nas atividades físicas do grupo. É possível que os fatores genéticos, por um aumento da sinalização da via RAS-MAPK, confiram um perfil mais magro a estes indivíduos, por acometimento não apenas da gordura, mas especialmente da musculatura / INTRODUCTION: RASopathies that include Noonan syndrome and Noonan related disorders (Noonan-like) are monogenic conditions with autosomal dominant inheritance caused by mutations in genes belonging to the same signaling pathway (RAS-MAPK). They are characterized by a multisystemic involvement in which short stature is a cardinal feature. The nutritional aspects are more frequently described in Noonan related disorders, in which feeding difficulties in the first months of life are more frequent and severe, requiring therapeutic intervention. OBJECTIVES: To evaluate the nutritional aspects of individuals with RASopathies, the energy and macronutrients consumption, according to age and sex; to compare the anthropometric data and dietary intake with population references and to establish a genotype-phenotype correlation. METHODS: The nutritional status of 62 individuals with Rasopathies confirmed by DNA analysis, with a median age of 12 years was evaluated by performing anthropometric measurements (weight, height, arm circumference and triceps skinfold thickness), analysis of habitual food intake and physical activity level. RESULTS: There was growth deficiency of postnatal origin in 48% of subjects and in the classification by body mass index, approximately 80% of them were classified as eutrophic or underweight/thinness. The parameters of body composition showed a decreased upper arm muscle circumference and in the classification by the upper arm fat area and upper arm muscle area, 43.5% had low fat reserves and 69% were malnourished or below average, respectively. Genotype-phenotype correlation showed that individuals with mutations in SHOC2, RAF1 and KRAS were those presenting the lowest mean values of stature and individuals with mutations in SHOC2, the lower median values of bone mass index. On the other hand, individuals with mutations in the BRAF had the highest median values. There was a statistically significant difference of the triceps skinfold thickness and upper arm fat area between Z-scores between BRAF and SHOC2 and of the triceps skinfold thickness Z-score between RAF1 and SHOC2. The energy and macronutrient intake of the subjects were similar to the dietary intake reference and the Brazilian population and in the level of physical activity, 65.4% were sedentary and irregularly active. It was found only one individual with significant difficulty in feeding, requiring gastrostomy. CONCLUSIONS: Short stature is common and more pronounced in individuals with mutations in SHOC2, RAF1 and KRAS. Opposed to the trend of the world\'s population of an increased prevalence of obesity, the majority of individuals with RASopathies present as eutrophic or underweight/ thinness. In body composition, there is an involvement of muscle tissue in all studied subjects. The decrease of these measures in the group is explained neither by a lower food intake nor by an increase in physical activity. It is possible that genetic factors, leading to hyperactivation of the RAS/ MAPK signaling, confer a slimmer profile to these individuals, mostly by the muscle involvement and not only by a decrease in fat reserve

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