Síndrome de Noonan 1: um relato de caso

Abstract

Noonan syndrome (NS) is a developmental disorder and, in most cases, it has an autosomal dominant inheritance, being characterized by several phenotypic anomalies, especially by short stature, congenital heart disease and facial dysmorphisms. It has an incidence of 1:1000 to 1:2500 births, with a similar prevalence between genders. The cause of SN is defined by the gene that the mutation is found, the most common being PTPN11 which is responsible for about 50% of cases, SOS1, KRAS, NRAS, SHOC2, CBL, and RAF1 which together, induced by ∼80 % of Noonan syndrome patients clinically diagnosed. The aim of this study was to report the clinical case of a patient with intellectual disability that includes the genomic diagnosis of Noonan syndrome 1 and to point out the importance of total sequencing of the exome for the diagnosis. The patient was referred for karyotyping, which does not show any numerical or structural changes, then a chromosomal microarray analysis was performed, which also showed no results in the number of pathogenic copies, and so he was conducted for the total exome sequencing. An origin de novo missense type mutation was found (112915455T> C, Phe285Ser) and the genetic diagnosis was established for the patient. Thus, it is important to highlight the fundamental role of total exome sequencing for the diagnosis of SN 1, in cases where there was no diagnosis after performing tests indicated as first choice.