Prenatal overgrowth and polydramnios: Would you think about Noonan syndrome?
Ontology highlight
ABSTRACT:
SUBMITTER: Beltrami B
PROVIDER: S-EPMC9393876 | biostudies-literature | 2022 Aug
REPOSITORIES: biostudies-literature
Publications
Prenatal overgrowth and polydramnios: Would you think about Noonan syndrome?
Beltrami Benedetta B Cerasani Jacopo J Consales Alessandra A Villa Roberta R Resta Nicoletta N Loconte Daria Carmela DC Boito Simona S Caschera Luca L Bassi Laura L Colombo Lorenzo L Iascone Maria M Bedeschi Maria Francesca MF
Clinical case reports 20220822 8
We report on a child with prenatal findings of increased nuchal translucency, polydramnios, ascites, and overgrowth. At birth, she presented length >97° centile, minor facial anomalies, megalencephaly, and Wolff-Parkinson-White syndrome. Whole-exome sequencing showed a pathogenic variant in the <i>NRAS</i> gene, but no mutations were found in <i>PI3K/AKT/mTOR</i> pathway genes. ...[more]
Similar Datasets
Project description:Noonan syndro me is a rare autosomal dominant congenital abnormality associated with a gene defect located on the short arm of chromosome 12. It is characterized by dysmorphic facies, webbed neck, short stature, lymphatic obstruction, cardiac anomalies, and intellectual disability. Prenatal diagnosis of Noonan syndrome is rare because there are no pathognomonic sonographic signs. Studies on the prenatal sonographic features of Noonan syndrome have been reported in very limited numbers. This case series of severe fetal Noonan syndrome, together with a literature review, was conducted to establish prenatal sonographic features highly suggestive of Noonan syndrome to facilitate early detection by clinicians. This study reveals that Noonan syndrome has a relatively specific pattern, which facilitates prenatal molecular genetic diagnosis. Increased nuchal translucency (NT) in the late first trimester and fluid collection in the early second trimester could be warning signs for follow-up, prompting further investigation to detect late-onset features and leading to molecular genetic confirmation. Most structural abnormalities appear in the second trimester, with progressive changes noted throughout gestation. This review better characterizes the sonographic features of fetal Noonan syndrome based on a larger sample size, illustrating a wider spectrum of prenatal phenotypes, including lymphatic drainage disorders, cardiac abnormalities, polyhydramnios, and absent ductus venosus.
| S-EPMC11476750 | biostudies-literature
Project description:In recent studies on prenatal testing for Noonan syndrome (NS) in fetuses with an increased nuchal translucency (NT) and a normal karyotype, mutations have been reported in 9-16% of cases. In this study, DNA of 75 fetuses with a normal karyotype and abnormal ultrasound findings was tested in a diagnostic setting for mutations in (a subset of) the four most commonly mutated NS genes. A de novo mutation in either PTPN11, KRAS or RAF1 was detected in 13 fetuses (17.3%). Ultrasound findings were increased NT, distended jugular lymphatic sacs (JLS), hydrothorax, renal anomalies, polyhydramnios, cystic hygroma, cardiac anomalies, hydrops fetalis and ascites. A second group, consisting of anonymized DNA of 60 other fetuses with sonographic abnormalities, was tested for mutations in 10 NS genes. In this group, five possible pathogenic mutations have been identified (in PTPN11 (n=2), RAF1, BRAF and MAP2K1 (each n=1)). We recommend prenatal testing of PTPN11, KRAS and RAF1 in pregnancies with an increased NT and at least one of the following additional features: polyhydramnios, hydrops fetalis, renal anomalies, distended JLS, hydrothorax, cardiac anomalies, cystic hygroma and ascites. If possible, mutation analysis of BRAF and MAP2K1 should be considered.
| S-EPMC3746261 | biostudies-other
Project description:Prenatal diagnosis of euploid increased nuchal translucency (NT) remains a challenge to obstetricians and genetic counselors although increased euploid NT at prenatal diagnosis can be associated with a favorable outcome. Prenatal diagnosis of euploid increased NT should include a differential diagnosis of pathogenetic copy number variants and RASopathy disorders (RDs) including Noonan syndrome (NS). Therefore, chromosomal microarray analysis, whole-exome sequencing, RD testing, and protein-tyrosine phosphatase, nonreceptor type 11 (PTPN11) gene testing may be necessary under such a circumstance. In this report, a comprehensive review of NS with its prenatal diagnosis and genetic testing is presented.
| S-EPMC9944828 | biostudies-literature
Project description:Noonan syndrome is a genetic multisystem disorder characterised by distinctive facial features, developmental delay, learning difficulties, short stature, congenital heart disease, renal anomalies, lymphatic malformations, and bleeding difficulties. Mutations that cause Noonan syndrome alter genes encoding proteins with roles in the RAS-MAPK pathway, leading to pathway dysregulation. Management guidelines have been developed. Several clinically relevant genotype-phenotype correlations aid risk assessment and patient management. Increased understanding of the pathophysiology of the disease could help development of pharmacogenetic treatments.
| S-EPMC4267483 | biostudies-literature
Project description:Large offspring syndrome (LOS) is a fetal overgrowth condition in bovines most often observed in offspring conceived with the use of assisted reproductive technologies (ART). Phenotypes observed in LOS include, overgrowth, enlarged tongues, umbilical hernias, muscle and skeleton malformations, abnormal organ growth and placental development. Although LOS cases have only been reported to be associated with ART, fetal overgrowth can occur spontaneously in cattle (S-LOS). S-LOS refers to oversized calves that are born at normal gestation lengths. ART-induced LOS has been characterized as an epigenetic syndrome, more specifically, a loss-of-imprinting condition. We propose that S-LOS is also a loss-of-imprinting condition.
| S-EPMC6527122 | biostudies-literature
Project description:Noonan syndrome (NS) is among the most common nonchromosomal disorders affecting development and growth. NS is genetically heterogeneous, being caused by germline mutations affecting various genes implicated in the RAS signaling network. This network transduces extracellular signals into intracellular biochemical and transcriptional responses controlling cell proliferation, differentiation, metabolism, and senescence. To explore the transcriptional consequences of NS-causing mutations, we performed global mRNA expression profiling on peripheral blood mononuclear cells obtained from 23 NS patients carrying heterozygous mutations in PTPN11 or SOS1. Gene expression profiling was also resolved in five subjects with Noonan-like syndrome with loose anagen hair (NS/LAH), a condition clinically related to NS and caused by an invariant mutation in SHOC2. Robust transcriptional signatures were found to specifically discriminate each of the three mutation groups from 21 age- and sex-matched controls. Despite the only partial overlap in terms of gene composition, the three signatures showed a notable concordance in terms of biological processes and regulatory circuits affected. These data establish expression profiling of peripheral blood mononuclear cells as a powerful tool to appreciate differential perturbations driven by germline mutations of transducers involved in RAS signaling and to dissect molecular mechanisms underlying NS and other RASopathies.
| S-EPMC3332054 | biostudies-literature
Project description:Noonan syndrome (NS) is a common genetic syndrome associated with gain of function variants in genes in the Ras/MAPK pathway. The phenotype of NS has been well characterized in populations of European descent with less attention given to other groups. In this study, individuals from diverse populations with NS were evaluated clinically and by facial analysis technology. Clinical data and images from 125 individuals with NS were obtained from 20 countries with an average age of 8 years and female composition of 46%. Individuals were grouped into categories of African descent (African), Asian, Latin American, and additional/other. Across these different population groups, NS was phenotypically similar with only 2 of 21 clinical elements showing a statistically significant difference. The most common clinical characteristics found in all population groups included widely spaced eyes and low-set ears in 80% or greater of participants, short stature in more than 70%, and pulmonary stenosis in roughly half of study individuals. Using facial analysis technology, we compared 161 Caucasian, African, Asian, and Latin American individuals with NS with 161 gender and age matched controls and found that sensitivity was equal to or greater than 94% for all groups, and specificity was equal to or greater than 90%. In summary, we present consistent clinical findings from global populations with NS and additionally demonstrate how facial analysis technology can support clinicians in making accurate NS diagnoses. This work will assist in earlier detection and in increasing recognition of NS throughout the world.
| S-EPMC5710841 | biostudies-literature
Project description:Noonan syndrome (NS) is an autosomal dominant disorder with vast heterogeneity in clinical and genetic features. Various symptoms have been reported for this abnormality such as short stature, unusual facial characteristics, congenital heart abnormalities, developmental complications, and an elevated tumor incidence rate. Noonan syndrome shares clinical features with other rare conditions, including LEOPARD syndrome, cardio-facio-cutaneous syndrome, Noonan-like syndrome with loose anagen hair, and Costello syndrome. Germline mutations in the RAS-MAPK (mitogen-activated protein kinase) signal transduction pathway are responsible for NS and other related disorders. Noonan syndrome diagnosis is primarily based on clinical features, but molecular testing should be performed to confirm it in patients. Due to the high number of genes associated with NS and other RASopathy disorders, next-generation sequencing is the best choice for diagnostic testing. Patients with NS also have higher risk for leukemia and specific solid tumors. Age-specific guidelines for the management of NS are available.
| S-EPMC5206377 | biostudies-literature
Project description:Noonan syndrome is a genetically heterogeneous disorder caused by mutations in PTPN11, SOS1, RAF1 and less frequently in KRAS, NRAS or SHOC2. Here, we performed mutation analysis of NRAS and SHOC2 in 115 PTPN11, SOS1, RAF1, and KRAS mutation-negative individuals. No SHOC2 mutations were found, but we identified 3 NRAS mutations in 3 probands. One NRAS mutation was novel. The phenotype associated with germline NRAS mutations is variable. Our results confirm that a small proportion of Noonan syndrome patients carry germline NRAS mutations.
| S-EPMC3398822 | biostudies-literature
Project description:Large (>90%) for gestational age (LGA) fetuses are usually identified incidentally. Detection of the LGA fetus should first prompt the provider to rule out incorrect dates and maternal diabetes. Once this is done, consideration should be given to certain overgrowth syndromes, especially if anomalies are present. The overgrowth syndromes have significant clinical and molecular overlap, and are associated with developmental delay, tumors, and other anomalies. Although genetic causes of overgrowth are considered postnatally, they are infrequently diagnosed prenatally. Here, we review prenatal sonographic findings in fetal overgrowth syndromes, including Pallister-Killian, Beckwith-Wiedemann, Sotos, Perlman, and Simpson-Golabi-Behmel. We also discuss prenatal diagnosis options and recurrence risks.
| S-EPMC4426974 | biostudies-literature