Combined PTPN11 and MYBPC3 Gene Mutations in an Adult Patient with Noonan Syndrome and Hypertrophic Cardiomyopathy

Genes (Basel). 2020 Aug 17;11(8):947. doi: 10.3390/genes11080947.

Abstract

In this report, an atypical case of Noonan syndrome (NS) associated with sarcomeric hypertrophic cardiomyopathy (HCM) in a 33-year-old patient was described. Genetic testing revealed two different disease-causing mutations: a mutation in the PTPN11 gene, explaining NS, and a mutation in the MYBPC3 gene, known to be associated with HCM. This case exemplifies the challenge in achieving a definite etiological diagnosis in patients with HCM and the need to exclude other diseases mimicking this condition (genocopies or phenocopies). Compound heterozygous mutations are rare but possible in HCM patients. In conclusion, this study highlights the important role of genetic testing as a necessary diagnostic tool for performing a definitive etiological diagnosis of HCM.

Keywords: Noonan syndrome; double mutations; hypertrophic cardiomyopathy.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Cardiomyopathy, Hypertrophic / complications
  • Cardiomyopathy, Hypertrophic / diagnosis*
  • Cardiomyopathy, Hypertrophic / genetics*
  • Carrier Proteins / genetics*
  • Facies
  • Female
  • Genetic Association Studies / methods
  • Genetic Predisposition to Disease
  • Humans
  • Mutation*
  • Noonan Syndrome / complications
  • Noonan Syndrome / diagnosis*
  • Noonan Syndrome / genetics*
  • Pedigree
  • Phenotype
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11 / genetics*

Substances

  • Carrier Proteins
  • myosin-binding protein C
  • PTPN11 protein, human
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11