A child presents with antimongoloid slant, pulmonary stenosis, short stature and undescended testis. The likely diagnosis is –
Noonan Syndrome : -

Autosomal dominant
Male or female with turner phenotype
Karyotype is normal
Congenital heart disease (Supravalvular pulmonary stenosis) 
Abnormalities of cardiac conduction and rhythum
Downslanting palpebral fissure (Antimongoloid slant)
Pectus carinatum or Pectus excavatum
Hypertelorism
Cryptorchidism (small testes)
Sensorineural hearing loss

Cardiac abnormality in Noonan's Syndrome

Most common → pulmonary stenosis (Supravalvular)
Hypertrophic cardiomyopathy
Abnormalities of cardiac conduction and rhythum
Short stature
Webbed neck
Low set ears
Cubitus valgus
Ptosis
Micrognathia
Clinodactyly
Delayed puberty
ASD
Coarctation of Aorta (rare)
Hypoparathyroidism
Noonan syndrome
Klinefelter syndrome
XYY sex chromosomes