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1.
J Clin Pediatr Dent ; 44(4): 262-267, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33167018

RESUMO

OBJECTIVE: To evaluate orodental, facial, clinical and molecular characteristics of the patients with Noonan Syndrome (NS). STUDY DESIGN: The orodental, clinical and molecular characteristics of 29 mutation-positive patients with NS were recorded. Orodental examination was performed in 17 patients. All exons and exonintron boundries of PTPN11 and SOS1 genes were analyzed by Sanger sequencing. RESULTS: A total of 29 patients with NS from 27 unrelated families were included in the study. Seventeen patients were examined by a specialist in oral medicine. The most common orodental findings were high-arched palate (n=13), gingivitis (n=6) and severe caries (n=6). Anterior open bite, posterior cross bite, Class II malocclusion, hypodontia, prognathism (maxillary or mandibular), macroglossia and gingival hyperplasia were also detected. Thirteen different mutations were observed in PTPN11 gene and exon 3 was the hotspot region. Hypodontia was detected in two patients who had the same mutation in PTPN11 gene, c.181G>A, p.D61N. CONCLUSION: This study indicated a high prevalance of orodental problems including high-arched palate, severe dental caries and gingivitis in patients with mutation-positive NS. The mutation in PTPN11 gene, c.181G>A, p.D61N, may be associated with hypodontia in patients with NS.


Assuntos
Cárie Dentária , Síndrome de Noonan , Mordida Aberta , Proteína Tirosina Fosfatase não Receptora Tipo 11 , Humanos , Mutação , Síndrome de Noonan/genética , Fenótipo , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética
2.
Mymensingh Med J ; 29(4): 1004-1009, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33116109

RESUMO

Noonan's syndrome is a developmental disorder characterized by short stature, typical facial dysmorphia, congenital heart defects and skeletal deformity. It may be sporadic or inherited as an autosomal dominant or recessive trait which occurs, one in 1000-2500 live births. We report a case of 16 years young girl presented to the hospital with short stature, Shortness of breath, morphologic features and congenital heart defect of Noonan Syndrome who has no similar history in the family and admitted in Bangabandhu Sheikh Mujib Medical University on 12th August 2018.


Assuntos
Cardiopatias Congênitas , Síndrome de Noonan , Feminino , Humanos , Síndrome de Noonan/diagnóstico , Síndrome de Noonan/genética , Fenótipo
3.
J Pharmacol Sci ; 144(3): 139-146, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32921395

RESUMO

SHP2 is a non-receptor protein tyrosine phosphatase encoded by the PTPN11 gene in human. Clinically, SHP2 has been identified as a causal factor of several diseases, such as Noonan syndrome, LEOPARD syndrome as well as myeloid malignancies. Interestingly, both loss-of-function and gain-of-function mutations occur in the PTPN11 gene. Analyses by biochemical and cell biological means as well as probing with small molecule compounds have demonstrated that SHP2 has both phosphatase-dependent and independent functions. In comparison with its phosphatase activity, the non-phosphatase-like function of SHP2 has not been well introduced or summarized. This review mainly focuses on the phosphatase-independent functions and its regulation by small molecule compounds as well as their use for disease therapy.


Assuntos
Monoéster Fosfórico Hidrolases , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/fisiologia , Cerebrosídeos , Depsipeptídeos , Mutação com Ganho de Função , Humanos , Síndrome LEOPARD/genética , Mutação com Perda de Função , Terapia de Alvo Molecular , Síndrome de Noonan/genética , Monoéster Fosfórico Hidrolases/metabolismo , Piperidinas , Proteína Tirosina Fosfatase não Receptora Tipo 11/antagonistas & inibidores , Pirimidinas , Transdução de Sinais/genética
4.
Clin Dermatol ; 38(4): 455-461, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32972603

RESUMO

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.


Assuntos
Síndrome de Costello/genética , Oftalmopatias/genética , Mutação em Linhagem Germinativa , Lipomatose/genética , Sistema de Sinalização das MAP Quinases/genética , Proteínas Monoméricas de Ligação ao GTP/genética , Síndromes Neurocutâneas/genética , Neurofibromatose 1/genética , Síndrome de Noonan/genética , Síndrome de Costello/diagnóstico , Síndrome de Costello/terapia , Oftalmopatias/diagnóstico por imagem , Oftalmopatias/terapia , Humanos , Lipomatose/diagnóstico por imagem , Lipomatose/terapia , Terapia de Alvo Molecular , Mutação , Síndromes Neurocutâneas/diagnóstico por imagem , Síndromes Neurocutâneas/terapia , Neurofibromatose 1/diagnóstico , Neurofibromatose 1/terapia , Síndrome de Noonan/diagnóstico , Síndrome de Noonan/terapia , Risco
5.
Am J Hum Genet ; 107(3): 499-513, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32721402

RESUMO

Signal transduction through the RAF-MEK-ERK pathway, the first described mitogen-associated protein kinase (MAPK) cascade, mediates multiple cellular processes and participates in early and late developmental programs. Aberrant signaling through this cascade contributes to oncogenesis and underlies the RASopathies, a family of cancer-prone disorders. Here, we report that de novo missense variants in MAPK1, encoding the mitogen-activated protein kinase 1 (i.e., extracellular signal-regulated protein kinase 2, ERK2), cause a neurodevelopmental disease within the RASopathy phenotypic spectrum, reminiscent of Noonan syndrome in some subjects. Pathogenic variants promote increased phosphorylation of the kinase, which enhances translocation to the nucleus and boosts MAPK signaling in vitro and in vivo. Two variant classes are identified, one of which directly disrupts binding to MKP3, a dual-specificity protein phosphatase negatively regulating ERK function. Importantly, signal dysregulation driven by pathogenic MAPK1 variants is stimulus reliant and retains dependence on MEK activity. Our data support a model in which the identified pathogenic variants operate with counteracting effects on MAPK1 function by differentially impacting the ability of the kinase to interact with regulators and substrates, which likely explains the minor role of these variants as driver events contributing to oncogenesis. After nearly 20 years from the discovery of the first gene implicated in Noonan syndrome, PTPN11, the last tier of the MAPK cascade joins the group of genes mutated in RASopathies.


Assuntos
Carcinogênese/genética , Proteína Quinase 1 Ativada por Mitógeno/genética , Transtornos do Neurodesenvolvimento/genética , Síndrome de Noonan/genética , Pré-Escolar , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/genética , Masculino , Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/patologia , Síndrome de Noonan/fisiopatologia , Fenótipo , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Transdução de Sinais , Sequenciamento Completo do Exoma , Proteínas ras/genética
6.
BMC Med Genet ; 21(1): 50, 2020 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-32164556

RESUMO

BACKGROUND: Noonan syndrome (NS), an autosomal dominant developmental genetic disorder, is caused by germline mutations in genes associated with the RAS / mitogen-activated protein kinase (MAPK) pathway. In several studies PTPN11 is one of the genes with a significant number of pathogenic variants in NS-affected patients. Therefore, clinically diagnosed NS individuals are initially tested for pathogenic variants in PTPN11 gene to confirm the relationship before studying genotype-phenotype correlation. METHODS: Individuals (363) with clinically diagnosed NS from four hospitals in South India were recruited and the exons of PTPN11 gene were sequenced. RESULTS: Thirty-two previously described pathogenic variants in eight different exons in PTPN11 gene were detected in 107 patients, of whom 10 were familial cases. Exons 3, 8 and 13 had the highest number of pathogenic variants. The most commonly identified pathogenic variants in this series were in exon 8 (c.922A > G, c.923A > G), observed in 22 of the affected. Congenital cardiac anomalies were present in 84% of the mutation-positive cohort, the majority being defects in the right side of the heart. The most common facial features were downward-slanting palpebral fissures, hypertelorism and low-set posteriorly rotated ears. Other clinical features included short stature (40%), pectus excavatum (54%) and, in males, unilateral or bilateral cryptorchidism (44%). CONCLUSION: The clinical features and mutational spectrum observed in our cohort are similar to those reported in other large studies done worldwide. This is the largest case series of NS-affected individuals with PTPN11 mutations described till date from India.


Assuntos
Síndrome de Noonan/genética , Polimorfismo de Nucleotídeo Único , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Adolescente , Adulto , Criança , Pré-Escolar , Estudos de Coortes , Análise Mutacional de DNA , Família , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Cardiopatias Congênitas/epidemiologia , Cardiopatias Congênitas/genética , Humanos , Índia/epidemiologia , Lactente , Recém-Nascido , Masculino , Síndrome de Noonan/epidemiologia , Fenótipo , Adulto Jovem
7.
Medwave ; 20(2): e7826, 2020 Feb 26.
Artigo em Espanhol | MEDLINE | ID: mdl-32119651

RESUMO

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.


Assuntos
Síndrome de Noonan/diagnóstico , Atenção Primária à Saúde , Adolescente , Equador , Humanos , Mutação , Síndrome de Noonan/genética , Síndrome de Noonan/terapia , Proteínas ras/genética
8.
BMC Gastroenterol ; 20(1): 34, 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32054441

RESUMO

BACKGROUND: Noonan syndrome is an autosomal dominant, variably expressed multisystem disorder characterized by specific facial and cardiac defects, delayed growth, ectodermal abnormalities, and lymphatic dysplasias. Lymphedema and chylous pleural effusions are common in Noonan syndrome, but protein-losing enteropathy (PLE) has only rarely been described in the condition and little is known about its genetic associations. CASE PRESENTATION: We report the case of a 30-year-old Chinese woman who developed severe recurrent edema and hypoproteinemia. Gastroduodenoscopy showed a "snowflake" appearance of lymphangiectasia in the duodenum, and CT reconstruction of the small intestine showed segmental thickening of the intestinal wall with localized stenosis. Whole exome sequencing revealed that the patient harbored a pathogenic variant of PTPN11 (c.A922G p.N308D), which was unfortunately inherited by her 2.5-year-old daughter who had short stature and atrial septal defect but no hypoproteinemia. CONCLUSIONS: This case of Noonan syndrome with PLE was associated with a PTPN11 mutation. A comprehensive review of PLE in Noonan syndrome revealed that PLE often presents late in this context but there is no clear genotype-phenotype correlation. Genetic evaluation with next-generation sequencing can be useful for securing the diagnosis and planning early intervention and management.


Assuntos
Síndrome de Noonan/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Enteropatias Perdedoras de Proteínas/genética , Adulto , Edema , Feminino , Estudos de Associação Genética , Humanos , Hipocalcemia , Hipoproteinemia , Mutação , Linhagem , Sequenciamento Completo do Exoma
9.
Int J Mol Sci ; 21(2)2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31936901

RESUMO

Noonan syndrome (NS) is a genetic disorder caused by the hyperactivation of the RAS-MAPK molecular pathway. About 50% of NS cases are caused by mutations affecting the SHP2 protein, a multi-domain phosphatase with a fundamental role in the regulation of the RAS-MAPK pathway. Most NS-causing mutations influence the stability of the inactive form of SHP2. However, one NS-causing mutation, namely T42A, occurs in the binding pocket of the N-SH2 domain of the protein. Here, we present a quantitative characterization of the effect of the T42A mutation on the binding of the N-terminal SH2 domain of SHP2 with a peptide mimicking Gab2, a fundamental interaction that triggers the activation of the phosphatase in the cellular environment. Our results show that whilst the T42A mutation does not affect the association rate constant with the ligand, it causes a dramatic increase of the affinity for Gab2. This effect is due to a remarkable decrease of the microscopic dissociation rate constant of over two orders of magnitudes. In an effort to investigate the molecular basis of the T42A mutation in causing Noonan syndrome, we also compare the experimental results with a more conservative variant, T42S. Our findings are discussed in the context of the structural data available on SHP2.


Assuntos
Predisposição Genética para Doença/genética , Mutação , Síndrome de Noonan/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/química , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Proteínas Adaptadoras de Transdução de Sinal , Humanos , Cinética , Modelos Moleculares , Mutagênese , Ligação Proteica , Conformação Proteica , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Domínios de Homologia de src
10.
Eur J Med Genet ; 63(1): 103617, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30664951

RESUMO

Mutations in LZTR1, already known to be causal in familial schwannomatosis type 2, have been recently involved in a small proportion of patients with autosomal dominant and autosomal recessive Noonan syndrome. LZTR1 is also a driver gene in non syndromal glioblastoma. We report a 26-year-old patient with typical Noonan syndrome, and the dominantly transmitted c.850C > T (p.(Arg284Cys)) variant in LZTR1. An oligoastrocytoma was diagnosed in the patient at the age of 22 years; recurrence of the tumor occurred at age 26, as a ganglioblastoma. The patient had been transiently treated with growth hormone between ages 15 and 17. Considering the implication of LZTR1 in sporadic tumors of the nervous system, we hypothesize that gliomas are a possible complication of LZTR1-related Noonan syndrome. This report also supports a possible link between occurrence of a cerebral tumor in Noonan syndrome and a previous treatment with growth hormone.


Assuntos
Astrocitoma/genética , Glioblastoma/genética , Síndrome de Noonan/genética , Fatores de Transcrição/genética , Adolescente , Adulto , Astrocitoma/complicações , Astrocitoma/diagnóstico , Astrocitoma/patologia , Feminino , Predisposição Genética para Doença , Glioblastoma/complicações , Glioblastoma/diagnóstico , Glioblastoma/patologia , Humanos , Masculino , Mutação , Síndrome de Noonan/complicações , Síndrome de Noonan/diagnóstico , Síndrome de Noonan/patologia , Linhagem
12.
Circ Genom Precis Med ; 12(11): e002648, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31638832

RESUMO

BACKGROUND: MRAS was identified recently as a novel Noonan syndrome (NS)-susceptibility gene. Phenotypically, both patients with NS, harboring pathogenic MRAS variants, displayed severe cardiac hypertrophy. This study aimed to demonstrate both the necessity and sufficiency of a patient-specific variant (p.Gly23Val-MRAS) to cause NS through the generation and characterization of patient-specific, isogenic control, and disease modeled induced pluripotent stem cell (iPSC) lines. METHODS: iPSCs were derived from a patient with a p.Gly23Val-MRAS variant to assess the effect of MRAS variants on pathogenesis of NS-associated cardiac hypertrophy. CRISPR/Cas9 gene editing was used to correct the pathogenic p.Gly23Val-MRAS variant in patient cells (isogenic control) and to introduce the pathogenic variant into unrelated control cells (disease modeled) to determine the necessity and sufficiency of the p.Gly23Val-MRAS variant to elicit the disease phenotype in iPSC-derived cardiomyocytes (iPSC-CMs). iPSC-CMs were analyzed by microscopy and immunofluroesence, single-cell RNAseq, Western blot, room temperature-quantitative polymerase chain reaction, and live-cell calcium imaging to define an in vitro phenotype of MRAS-mediated cardiac hypertrophy. RESULTS: Compared with controls, both patient and disease modeled iPSC-CMs were significantly larger and demonstrated changes in gene expression and intracellular pathway signaling characteristic of cardiac hypertrophy. Additionally, patient and disease modeled iPSC-CMs displayed impaired Ca2+ handling, including increased frequency of irregular Ca2+ transients and changes in Ca2+ handling kinetics. CONCLUSIONS: p.Gly23Val-MRAS is both necessary and sufficient to elicit a cardiac hypertrophy phenotype in iPSC-CMs that includes increased cell size, changes in cardiac gene expression, and abnormal calcium handling-providing further evidence to establish the monogenetic pathogenicity of p.Gly23Val-MRAS in NS with cardiac hypertrophy.


Assuntos
Cardiomegalia/genética , Células-Tronco Pluripotentes Induzidas/metabolismo , Miócitos Cardíacos/metabolismo , Síndrome de Noonan/genética , Proteínas ras/genética , Sequência de Bases , Cardiomegalia/metabolismo , Células Cultivadas , Feminino , Predisposição Genética para Doença , Humanos , Mutação , Fenótipo , Proteínas ras/metabolismo
13.
Am J Med Genet A ; 179(12): 2433-2446, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31566897

RESUMO

While neurofibromatosis type 1 (NF1) and Noonan syndrome (NS) are clinically distinct genetic syndromes, they have overlapping features because they are caused by pathogenic variants in genes encoding molecules within the Ras-mitogen-activated protein kinase signaling pathway. Increased risk for emotional and behavioral challenges has been reported in both children and adults with these syndromes. The current study examined parent-report and self-report measures of emotional functioning among children with NF1 and NS as compared to their unaffected siblings. Parents and children with NS (n = 39), NF1 (n = 39), and their siblings without a genetic condition (n = 32) completed well-validated clinical symptom rating scales. Results from parent questionnaires indicated greater symptomatology on scales measuring internalizing behaviors and symptoms of attention deficit hyperactivity disorder (ADHD) in both syndrome groups as compared with unaffected children. Frequency and severity of emotional and behavioral symptoms were remarkably similar across the two clinical groups. Symptoms of depression and anxiety were higher in children who were also rated as meeting symptom criteria for ADHD. While self-report ratings by children generally correlated with parent ratings, symptom severity was less pronounced. Among unaffected siblings, parent ratings indicated higher than expected levels of anxiety. Study findings may assist with guiding family-based interventions to address emotional challenges.


Assuntos
Emoções , Neurofibromatose 1/diagnóstico , Síndrome de Noonan/diagnóstico , Adolescente , Fatores Etários , Criança , Comportamento Infantil , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Masculino , Neurofibromatose 1/genética , Síndrome de Noonan/genética , Pais , Fenótipo , Autorrelato , Irmãos , Inquéritos e Questionários
14.
Am J Med Genet A ; 179(12): 2474-2480, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31584751

RESUMO

Noonan syndrome-like disorder with loose anagen hair (NS/LAH) is one of the RASopathies, a group of clinically related developmental disorders caused by germline mutations in genes that encode components acting in the RAS/MAPK pathway. Among RASopathies, NS/LAH (OMIM 607721) is an extremely rare, multiple anomaly syndrome characterized by dysmorphic facial features similar to those observed in Noonan syndrome along with some distinctive ectodermal findings including easily pluckable, sparse, thin, and slow-growing hair. ADA2 deficiency (DADA2, OMIM 615688) is a monogenic autoinflammatory disorder caused by homozygous or compound heterozygous mutations in ADA2, with clinical features including recurrent fever, livedo racemosa, hepatosplenomegaly, and strokes as well as immune dysregulation. This is the first report of NS/LAH and ADA2 deficiency in the same individual. We report on a patient presenting with facial features, recurrent infections and ectodermal findings in whom both the clinical and molecular diagnoses of NS/LAH and ADA2 deficiency were established, respectively.


Assuntos
Adenosina Desaminase/deficiência , Agamaglobulinemia/diagnóstico , Agamaglobulinemia/genética , Peptídeos e Proteínas de Sinalização Intercelular/deficiência , Síndrome dos Cabelos Anágenos Frouxos/diagnóstico , Síndrome dos Cabelos Anágenos Frouxos/genética , Síndrome de Noonan/diagnóstico , Síndrome de Noonan/genética , Fenótipo , Imunodeficiência Combinada Severa/diagnóstico , Imunodeficiência Combinada Severa/genética , Adenosina Desaminase/genética , Alelos , Estudos de Associação Genética/métodos , Predisposição Genética para Doença , Genótipo , Humanos , Mutação , Radiografia , Avaliação de Sintomas
15.
Arch Argent Pediatr ; 117(5): 330-337, 2019 10 01.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-31560489

RESUMO

INTRODUCTION: RASopathies are a set of syndromes with phenotypic overlapping features caused by gene mutations involved in the RAS/MAPK pathway. They are autosomal dominantly inherited and share common clinical characteristics, including short stature, craniofacial dysmorphisms, congenital heart disease, ectodermal manifestations, and a higher risk for cancer. A molecular diagnosis is a key factor. OBJECTIVE: To identify PTPN11, SOS1, RAF1, BRAF, and HRAS mutations and compare the main clinical characteristics of patients with molecular confirmation. Population and methods. Children with a clinical diagnosis of RASopathy assessed between August 2013 and February 2017. RESULTS: Mutations were identified in 71 % (87/122) of patients. The molecular test confirmed diagnosis in 73 % of patients with Noonan syndrome. The most prevalent mutation was c.922A>G (p.Asn308Asp) in the PTPN11 gene. A previously undescribed variant in RAF1 was detected: c.1467G>>C (p.Leu489Phe). Cardiofaciocutaneous syndrome was confirmed in 67 % of cases with BRAF mutations. Costello syndrome and Noonan syndrome with multiple lentigines were confirmed in all cases. CONCLUSION: The confirmation of clinical diagnosis allowed for a more accurate differential diagnosis. The prevalence of PTPN11 (58 %), SOS1 (10 %), and RAF1 mutations (5 %) in children with Noonan syndrome, of PTPN11 mutations (100 %) in those with Noonan syndrome with multiple lentigines, of BRAF mutations (67 %) in those with cardiofaciocutaneous syndrome, and of HRAS mutations (100 %) in those with Costello syndrome was determined.


Assuntos
Síndrome de Costello/diagnóstico , Displasia Ectodérmica/diagnóstico , Insuficiência de Crescimento/diagnóstico , Cardiopatias Congênitas/diagnóstico , Síndrome de Noonan/diagnóstico , Adolescente , Argentina , Criança , Pré-Escolar , Síndrome de Costello/genética , Diagnóstico Diferencial , Displasia Ectodérmica/genética , Facies , Insuficiência de Crescimento/genética , Feminino , Cardiopatias Congênitas/genética , Humanos , Lactente , Recém-Nascido , Masculino , Mutação , Síndrome de Noonan/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas c-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteína SOS1/genética , Adulto Jovem
16.
Horm Res Paediatr ; 92(4): 269-275, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31533111

RESUMO

BACKGROUND: LZTR1 participates in RAS protein degradation, hence limiting the RAS/MAPK cascade. Pathogenic mutations in LZTR1 (MIM:600574) have been described in a few patients with Noonan syndrome (NS). Three patients with LZTR1 mutations of different genetic transmission and NS phenotype are herein characterized. CLINICAL CASES: Case 1 is a 5-year-old boy with NS phenotype. Sanger sequencing of PTPN11 and SOS1 identified no mutations. Whole exome sequencing (WES) detected a heterozygous missense mutation in LZTR1:c.742G>A (p.Gly248Arg) (exon 8, Kelch 4 functional domain). Bioinformatic algorithms predict a deleterious effect of this variant, previously described to cause NS. Case 2 is a 4-year-old boy with NS phenotype. Direct sequencing of 8 genes associated with NS identified no mutations. WES localized a homozygous missense mutation in LZTR1:c.2074T>C (p.Phe692Leu, exon 18). This mutation has not been reported before and is predicted to have a deleterious effect on the protein. Case 3 is an 8-year-old boy who shares NS phenotype with his mother. A multigene panel for RASopathies showed a heterozygous missense variant in LZTR1:c.730T>C (p.Ser244Pro) (exon 8; Kelch 4 functional domain) that was maternally inherited. This variant has not been previously described; however, in silico predictors classify it as deleterious. Familial segregation suggests its pathogenicity. CONCLUSIONS: The molecular approach for syndromic phenotypes associated with various genes should involve complete/updated panels or WES rather than gene-by-gene sequencing. RASopathy genetic panels should incorporate LZTR1. Patients with pathogenic mutations in LZTR1 exhibit a characteristic NS gestalt but variable cardiac, height, and neurodevelopment expressions, with recessive inheritance possibly associating with a more severe phenotype.


Assuntos
Mutação , Síndrome de Noonan/genética , Fatores de Transcrição/genética , Criança , Pré-Escolar , Genótipo , Humanos , Masculino , Fenótipo , Sequenciamento Completo do Exoma
17.
Am J Med Genet A ; 179(10): 2083-2090, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31368652

RESUMO

Noonan syndrome (NS) is caused by mutations in more than 10 genes, mainly PTPN11, SOS1, RAF1, and RIT1. Congenital heart defects and cardiomyopathy (CMP) are associated with significant morbidity and mortality in NS. Although hypertrophic CMP has "classically" been reported in association to RAF1, RIT1, and PTPN11 variants, SOS1 appears to be poorly related to CMP. Patients with NS attending our Center from January 2013 to June 2018 were eligible for inclusion if they carried SOS1 variants and presented with-or developed-CMP. Literature review describing the co-existence of SOS1 mutation and CMP was also performed. We identified six patients with SOS1 variants and CMP (male to female ratio 2:1) including two novel variants. CMP spectrum encompassed: (a) dilated CMP, (b) nonobstructive hypertrophic CMPs, and (c) obstructive hypertrophic CMPs. Survival is 100%. Literature review included 16 SOS1 mutated in CMP. CMP, mainly hypertrophic, has been often reported in association to RAF1, RIT1, and PTPN11 variants. Differently from previous reports, due to the frequent association of SOS1 variants and CMP in our single center experience, we suggest potential underestimated proportion of SOS1 in pediatric CMPs.


Assuntos
Cardiomiopatias/complicações , Cardiomiopatias/genética , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/genética , Mutação/genética , Síndrome de Noonan/complicações , Síndrome de Noonan/genética , Proteína SOS1/genética , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Adulto Jovem
18.
Artigo em Chinês | MEDLINE | ID: mdl-31446693

RESUMO

Summary Noonan syndrome with multiple lentigines(NSML) is a disorder with syndromic hearing loss. Abnormalities of other systems in NSML have received increasing attention, but hearing loss is rarely concerned. And due to the incomplete phenotype, some patients with NSML maybe missed or maybe confused with other syndromic deafness such as Waardenburg syndrome. Our study will familiarize more otolaryngologists with Leopard syndrome. A 5-year-old boy with bilateral sensorineural hearing loss and numerous symmetrically distributed dark brown macules that had good effect of cochlear implantation was collected in this study. And his father had bilateral sensorineural hearing loss and numerous symmetrically distributed dark brown macules. Waardenburg syndrome was initially diagnosed by clinical phenotype and its molecular etiology was confirmed by gene diagnosis. Waardenburg syndrome-related deafness genes and 131 known deafness genes were not identified by second-generation sequencing. Whole-exon sequencing was performed for 4 individuals in the family and the results were confirmed by Sanger sequencing. This study confirmed the diagnosis by identifying a disease-causing mutation in the PTPN11 gene, which was a heterozygous missense mutation at p. Tyr279Cys(c. 836A>G). The mutation co-segregated with hearing loss in the family. Our results demonstrated that hearing loss in this family was caused by heterozygous mutations in PTPN11. These cases will familiarize more otolaryngologists with NSML, and they emphasize the importance of considering NSML as a possible cause of hearing problems.


Assuntos
Surdez/genética , Síndrome de Noonan/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Pré-Escolar , Heterozigoto , Humanos , Masculino , Mutação , Síndrome de Waardenburg
19.
Artigo em Chinês | MEDLINE | ID: mdl-31446698

RESUMO

Summary PTPN11 gene encodes tyrosine phosphatase SHP-2 which locates on chromosome 12(12q24.1), expresses in most embryonic and adult tissues, and plays pivotal roles in cell proliferation, differentiation, survival and cell death. SHP-2 apparently participates in signaling events downstream of RAS-MAPK and JAK/STAT. Diseases related to PTPN11 gene mutations include the Noonan syndrome(NS) and the NS with Multiple Lentigines(NSML). Both NS and NSML contain the phenotypes of deafness, craniofacial anomalies, short stature, congenital heart defects, skin disorders, ophthalmologic abnormalities and cancer predisposition.


Assuntos
Surdez/genética , Síndrome de Noonan/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Humanos , Mutação , Síndrome de Noonan/classificação , Fenótipo , Transdução de Sinais
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