A cardiofacial syndrome with a variable phenotype, which may change with age, many characteristics of which overlap those of the Turner syndrome. Short stature and mild mental retardation are the main features of this syndrome. Webbed neck, heart defects, chest deformities, characteristic facial features, and other abnormalities, and occasional hyperpyrexia may be associated. Cardiofaciocutaneous and Noonan syndromes are sometimes considered the same entity.