Complicated ventricular arrhythmia and hematologic myeloproliferative disorder in RIT1-associated Noonan syndrome: Expanding the phenotype and review of the literature.
Noonan syndrome
accelerated idioventricular rhythm
monocytosis
myeloproliferative disorder
Journal
Molecular genetics & genomic medicine
ISSN: 2324-9269
Titre abrégé: Mol Genet Genomic Med
Pays: United States
ID NLM: 101603758
Informations de publication
Date de publication:
07 2020
07 2020
Historique:
received:
07
11
2019
accepted:
20
03
2020
pubmed:
13
5
2020
medline:
1
5
2021
entrez:
13
5
2020
Statut:
ppublish
Résumé
Noonan syndrome is an autosomal dominant disorder secondary to RASopathies, which are caused by germ-line mutations in genes encoding components of the RAS mitogen-activated protein kinase pathway. RIT1 (OMIM *609591) was recently reported as a disease gene for Noonan syndrome. We present a patient with RIT1-associated Noonan syndrome, who in addition to the congenital heart defect, had monocytosis, myeloproliferative disorder, and accelerated idioventricular rhythm that was associated with severe hemodynamic instability. Noonan syndrome was suspected given the severe pulmonary stenosis, persistent monocytosis, and "left-shifted" complete blood counts without any evidence of an infectious process. Genetic testing revealed that the patient had a heterozygous c.221 C>G (pAla74Gly) mutation in the RIT1. We report a case of neonatal Noonan syndrome associated with RIT1 mutation. The clinical suspicion for Noonan syndrome was based only on the congenital heart defect, persistent monocytosis, and myeloproliferative process as the child lacked all other hallmarks characteristics of Noonan syndrome. However, the patient had an unusually malignant ventricular dysrhythmia that lead to his demise. The case highlights the fact that despite its heterogeneous presentation, RIT1-associated Noonan syndrome can be extremely severe with poor outcome.
Sections du résumé
BACKGROUND
Noonan syndrome is an autosomal dominant disorder secondary to RASopathies, which are caused by germ-line mutations in genes encoding components of the RAS mitogen-activated protein kinase pathway. RIT1 (OMIM *609591) was recently reported as a disease gene for Noonan syndrome.
METHODS AND RESULTS
We present a patient with RIT1-associated Noonan syndrome, who in addition to the congenital heart defect, had monocytosis, myeloproliferative disorder, and accelerated idioventricular rhythm that was associated with severe hemodynamic instability. Noonan syndrome was suspected given the severe pulmonary stenosis, persistent monocytosis, and "left-shifted" complete blood counts without any evidence of an infectious process. Genetic testing revealed that the patient had a heterozygous c.221 C>G (pAla74Gly) mutation in the RIT1.
CONCLUSION
We report a case of neonatal Noonan syndrome associated with RIT1 mutation. The clinical suspicion for Noonan syndrome was based only on the congenital heart defect, persistent monocytosis, and myeloproliferative process as the child lacked all other hallmarks characteristics of Noonan syndrome. However, the patient had an unusually malignant ventricular dysrhythmia that lead to his demise. The case highlights the fact that despite its heterogeneous presentation, RIT1-associated Noonan syndrome can be extremely severe with poor outcome.
Identifiants
pubmed: 32396283
doi: 10.1002/mgg3.1253
pmc: PMC7336743
doi:
Substances chimiques
RIT1 protein, human
EC 3.6.1.-
ras Proteins
EC 3.6.5.2
Types de publication
Case Reports
Journal Article
Review
Langues
eng
Sous-ensembles de citation
IM
Pagination
e1253Informations de copyright
© 2020 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.
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