Variable phenotypic expression in a large Noonan syndrome family segregating a novel SOS1 mutation

Am J Med Genet A. 2017 Nov;173(11):2968-2972. doi: 10.1002/ajmg.a.38466. Epub 2017 Sep 8.

Abstract

Noonan syndrome (NS) is an autosomal dominant multisystem condition with a variable phenotype. The most characteristic features are short stature, congenital heart defects, and recognizable facial features. Mutations in SOS1 are found in 10-20% of patients with NS. Different genotype-phenotype studies mention correlations between SOS1 mutations and some features, such as ectodermal abnormalities and specific facial features. We present a large NS family with a novel pathogenic mutation; SOS1 c.3134C>G, p.Pro1045Arg. Ten family members with NS are included with genetically confirmed mutation and clinical evaluation. The phenotype shows a broad spectrum from only few suggestive features for NS in the older generation to typical features in the youngest generation. We report on a novel pathogenic mutation in the SOS1 gene and a large clinical spectrum in a NS family with ten genetically confirmed affected individuals.

Keywords: Noonan syndrome; SOS1 mutation; genotype-phenotype correlation; intra-familial variability.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Female
  • Genetic Association Studies
  • Heart Defects, Congenital / complications
  • Heart Defects, Congenital / genetics*
  • Heart Defects, Congenital / physiopathology
  • Heterozygote
  • Humans
  • Male
  • Middle Aged
  • Mutation
  • Noonan Syndrome / complications
  • Noonan Syndrome / genetics*
  • Noonan Syndrome / physiopathology
  • Pedigree
  • Phenotype
  • SOS1 Protein / genetics*
  • Young Adult

Substances

  • SOS1 Protein