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Atypical, severe hypertrophic cardiomyopathy in a newborn presenting Noonan syndrome harboring a recurrent heterozygous MRAS variant
Author(s) -
Pires Lucas Vieira Lacerda,
Bordim Renata de Almeida,
Maciel Maria Beatriz Rabelo,
Tanaka Ana Cristina Sayuri,
Yamamoto Guilherme Lopes,
Honjo Rachel Sayuri,
Kim Chong Ae,
Bertola Debora Romeo
Publication year - 2021
Publication title -
american journal of medical genetics part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.064
H-Index - 112
eISSN - 1552-4833
pISSN - 1552-4825
DOI - 10.1002/ajmg.a.62376
Subject(s) - noonan syndrome , mras , hypertrophic cardiomyopathy , medicine , missense mutation , short stature , germline , cardiology , genetics , biology , phenotype , gene , voltage , induction motor , physics , vector control , quantum mechanics
Noonan syndrome (NS) is a Mendelian phenotype, member of a group of disorders sharing neurocardiofaciocutaneous involvement, known as RASopathies, caused by germline variants in genes coding for components of the RAS/MAPK signaling pathway. Recently, a novel gene of the RAS family ( MRAS ) was reported to be associated with NS in five children, all of them presenting, among the cardinal features of NS, the same cardiac finding, hypertrophic cardiomyopathy (HCM). We report on a 2‐month‐old infant boy also presenting this cardiac anomaly that evolved to a fatal outcome after a surgical myectomy. In addition, a thick walled left ventricle apical aneurysm, rarely described in NS, was also disclosed. Next‐generation sequencing revealed a missense, previously reported variant in MRAS (p.Thr68Ile). This report reinforces the high frequency of HCM among individuals harboring MRAS variants, contrasting to the 20% overall prevalence of this cardiac anomaly in NS. Thus, these preliminary data suggest that variants in MRAS per se are high risk factors for the development of an early, severe HCM, mostly of them with left ventricle outflow tract obstruction, with poor prognosis. Because of the severity of the cardiac involvement, other clinical findings could not be addressed in detail. Therefore, long‐term follow‐up of these individuals and further descriptions are required to fully understand the complete phenotypic spectrum of NS associated with MRAS germline variants, including if these individuals present an increased risk for cancer.