Noonan's syndrome, or pseudo-Turner's syndrome, is a dominantly inherited condition with features similar to Turner's syndrome (such as webbed neck, ptosis, short stature, wide-carrying angle, and lymphoedema), as well as features different from Turner's syndrome (such as normal karyotype, triangle-shaped face, pectus excavatum, right-sided heart disease and, commonly, mental retardation). Affected males may have undescended, often functionally impaired, testes.
