This it is an autosomal dominant disorder that leads to short stature, cubitus valgus, neck webbing, congenital lymphedema, and congenital heart defects similar to that of Turner syndrome. Both males and females are affected and manifest deformity of the sternum, mental dullness, typical hypertelorism, and drooping of the eyelid (ptosis). Cardiac manifestations include valvular pulmonary stenosis; the valve cusps are thickened and dysplastic and a right-sided flow may be impeded by obstruction because of pulmonary artery hypoplasia. In more than one-third of patients an atrial septal defect occurs often in association with pulmonary valve stenosis.