Manifestaciones otorrinolaringológicas del síndrome de Noonan / Otorhinolaryngologic manifestations of Noonan síndrome / Manifestações otorrinolaringológicas da síndrome de noonan

El síndrome de Noonan (SN) es un trastorno genético de herencia autosómica dominante relativamente frecuente. Clásicamente se ha descrito como la asociación de talla baja, dismorfias craneofaciales (fundamentalmente hipertelorismo, inclinación hacia abajo de las hendiduras palpebrales, ptosis palpebral, pabellones auriculares rotados y de implantación baja, hélix grueso), cardiopatía congénita (característicamente estenosis pulmonar valvular -EP- y miocardiopatía hipertrófica -MCH-), malformaciones torácicas(pectus excavatum/carinatum, tórax amplio) y criptorquidia en los varones. Tiene una incidencia alta, de 1/1.000- ½.500 neonatos.

Noonan syndrome (NS) is a genetic disorder relatively common autosomal dominant inheritance. Classically described as the association of short stature, craniofacial dysmorphia (hypertelorism, palpebral ptosis, ear low – set ears), congenital heart disease (typically valvular pulmonary stenosis -PSand hypertrophic cardiomyopathy -HCM-), thoracic malformations (pectus excavatum / carinatum, broad chest) and cryptorchidism in men. It has a high incidence of 1 / 1,000- 1 / 2,500 newborns.(1).

A síndrome de Noonan (SN) é um transtorno genético de herança autossômica dominante relativamente frequente. Classicamente, foi descrita como a associação de baixa estatura, dismorfias craniofaciais (fundamentalmente hipertelorismo, inclinação para baixo das fendas palpebrais, ptose palpebral, pavilhões auriculares rotados e de implantação baixa, hélix grosso), cardiopatia congênita (caracteristicamente estenose pulmonar valvular -EP- e miocardiopatia hipertrófica -MCH-), más formações torácicas (pectus excavatum/carinatum, tórax amplo) e criptorquidia nos meninos. (1) Tem uma incidência alta de 1/1.000- ½.500 neo-natos.

Determinantes genéticos na síndrome de Noonan e nas síndromes Noonan-like: investigação clínica e molecular / Genetic determinants in Noonan syndrome and in Noonan-like syndromes: clinical and molecular study

A síndrome de Noonan (SN) é uma doença de herança autossômica, relativamente frequente na população e que apresenta heterogeneidade genética. Caracteriza-se por dismorfismos faciais, baixa estatura, pescoço curto/alado, alterações cardíacas, deformidades esternais e criptorquia. A SN apresenta sobreposição dos achados clínicos com outras síndromes mais raras, denominadas síndromes Noonan-like (SNL): síndrome cardio-facio-cutânea (CFC), síndrome de Costello (SC), neurofibromatose-síndrome de Noonan (NFSN), síndrome de Noonan com manchas lentiginosas/síndrome de LEOPARD (SL), síndrome de Noonan-like com perda de cabelos anágenos (SNL-PCA) e síndrome de Noonan-like com leucemia mielomonocítica juvenil (SNL-LMMJ). As SN e SNL decorrem de mutações em genes pertencentes à via de sinalização RAS/MAPK alguns dos quais são protooncogenes, o que tem despertado o interesse na caracterização do risco de desenvolvimento de neoplasias nessas síndromes. Os objetivos deste estudo visam o sequencimento conjunto dos genes PTPN11, SOS1, RAF1, KRAS, SHOC2, BRAF e HRAS em pacientes com diagnóstico clínico das SN e SNL a fim de: determinar a frequência de mutação; estabelecer uma correlação genótipo-fenótipo; estabelecer um fluxograma para o estudo molecular a partir dos hotspots; e avaliar se a variabilidade fenotípica apresentada nos pacientes com SN pode ser explicada pela presença de mutações em mais de um gene da via RAS/MAPK. Foram avaliados 194 probandos - 152 com SN e 42 com SNL (19 CFC, 15 NFNS, 4 CS e 4 LS). Mutações foram identificadas em 99 pacientes 80 com SN (53%); 19 com SNL. Apenas um paciente com SN apresentou mutação em dois genes da via RAS/MAPK (PTPN11 e SOS1). O estudo molecular na SN mostrou, assim como na literatura, um maior envolvimento do gene PTPN11 (34%), seguido dos genes SOS1 (12%) e RAF1 (7%). A comparação dos achados clínicos, levando em consideração as alterações gênicas, também confirma as correlações já descritas na literatura; entre elas...

Noonan syndrome (NS) is a relatively common, autosomal dominant disease that presents a marked genetic heterogeneity. It is characterized by facial dysmorphisms, short stature, webbed/short neck, cardiac abnormalities, esternal anomalies and cryptorchidism. NS shows clinical overlap of some of its findings with other rarer syndromes, known as Noonan-like syndromes (NLS): cardio-facio-cutaneous syndrome (CFC), Costello syndrome (CS), neurofibromatosis-Noonan syndrome (NFNS), Noonan syndrome with lentiginous stains/LEOPARD syndrome (LS), Noonan-like syndrome with loose anagen hair (NLS-LAH) and Noonan-like syndrome with juvenile myelomonocytic leukemia (NLS-JMML). NS and NLS are related to mutations in genes belonging of RAS-MAPK signaling pathway. Some of these genes are classified as proto-oncogenes. This fact also arouses the interest in the characterization of the risk for cancer development in this group of patients. The objectives of this study are to sequence the genes associated with NS and NLS (PTPN11, SOS1, RAF1, KRAS, SHOC2, HRAS and BRAF) in patients that fulfilled clinical diagnostic criteria for NS or NLS to: determine the frequency of the mutations; establish a genotype-phenotype correlation; estabilish a flowchart for molecular study from the hotspots; and evaluate when the phenotypic variability presented in NS patients can be explained by the presence of mutations in more than one gene of the RAS/MAPK pathway. This study evaluated 194 probands 152 with NS e 42 with NLS (19 CFC, 15 NFSN, 4 SC e 4 SL). Mutations were identified in 99 patients 80 with NS (53%), 19 with NLS. Only one patient presented mutation in two different genes of the RAS/MAPK pathway (PTPN11 and SOS1). The molecular analysis showed a predominance of mutations in the PTPN11 gene (34%), followed by the SOS1 (12%) and RAF1 (7%) genes in patients with NS, in accordance with the literature. Patients with NS and mutation in the: PTPN11 gene, presented a higher frequency of...

Phenotypic implications of cytogenetic findings in female patients with short ststure turner and noonan syndromes

This study included 37 females with short stature and/or delayed puberty. They were subjected to complete clinical genetic examination, X-rays, cytogenetic analysis and anthropometric measurements, which included 14 measurements and 8 derived indices. Patients with structural abnormality of X chromosome [22.6%] showed mild phenotypic manifestations, while the mosaic group [32.3%] exhibited a phenotype moderate in severity. Analysis of the anthropometric measurements and indices showed that TS had an abnormal growth pattern more evident in pure TS and mosaic groups. Comparison between patients with TS [83.8%] and Noonan syndrome [16.2%] showed that both had tendency to growth retardation with similar growth pattern in the 2 conditions. Early diagnosis, assessment of growth with follow up will aid in both management and genetic counseling in Turner and Noonan syndromes