Noonan syndrome

Also known as: Male Turner syndrome; Turner phenotype with normal karyotype

RASopathy with pulmonary valve stenosis, hypertrophic cardiomyopathy, short stature and distinctive facies.

Medical specialty: Cardiology
Subspecialty: Cardiology / Genetic cardiology
Sex & age distribution: Male: affected; Female: affected equally; Children: yes, congenital
Gene(s) involved: BRAF, CBL, KRAS, LZTR1, MAP2K1, MRAS, NRAS, PTPN11, RAF1, RIT1, RRAS2, SHOC2, SOS1, SOS2

Etiology & mechanism

Hyperactivated RAS–MAPK signaling.

Gene(s) involved (14)

BRAFCBLKRASLZTR1MAP2K1MRASNRASPTPN11RAF1RIT1RRAS2SHOC2SOS1SOS2

Symptoms & signs (11)

bleeding diathesiscryptorchidismdevelopmental delayhypertelorismhypertrophic cardiomyopathylow-set earspectus deformityptosispulmonary valve stenosisshort staturewebbed neck

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