The child presenting with the antimongoloid slant, pulmonary stenosis, sho stature, and undescended testis is suggestive of Noonan syndrome. Noonan syndrome: Autosomal-dominant disorder (12q) Male or female with Turner phenotype; normal karyotype Clinical features: Down-slanting palpebral fissure (antimongoloid slant) Pectus carinatum Hypeelorism Cryptorchidism Low levels of clotting factor 11 and 12 Leukemia (Juvenile chronic myelogenous leukemia) Moderate mental retardation in 25% Cardiac abnormality: Most common is pulmonary valve stenosis Hyperophic cardiomyopathy Atrial septal defect Coarctation of aoa Sho stature, webbed neck, low set ears, cubitus valgus: Similarities with Turner syndrome Ptosis, micrognathia, Clinodactyly, delayed pubey Difference between Noonan syndrome and Turner&;s syndrome: Noonan syndrome Turner Syndrome Normal karyotype (46XX/46XY) 45,XO(60%) Most common hea disease: Valvular pulmonary stenosis Most common hea disease: Bicuspid aoic valve 25% have mental retardation Mental retardation rare Genitourinary: Genitourinary: Female: Feile, delayed pubey Female: Infeile, Streak ovaries Male: Infeile due to cryptorchidism No males Ref: nelson textbook of pediatrics 21st edition Pgno: 669,2995