Vginal agenesis
Müllerian agenesis, also referred to as Mayer–Rokitansky–Küster–Hauser syndrome, or vaginal agenesis, has an incidence of 1 per 4,500–5,000 females. Müllerian agenesis is caused by embryologic underdevelopment of the müllerian duct, with resultant agenesis or atresia of the vagina, uterus, or both. The vaginal canal is markedly shortened and may appear as a dimple below the urethra. The ovaries are typically normal in structure and function, though they may be found in atypical locations.
Patients with müllerian agenesis usually are identified when they are evaluated for primary amenorrhea with otherwise typical growth and pubertal development. Müllerian agenesis is one of the most common causes of primary amenorrhea in patients with typical breast development and hair at pubis and armpits. On physical examination, patients with müllerian agenesis have normal height, breast development, body hair, and external genitalia. The vagina is present and may appear as a small flush dimple, or longer, without a cervix at the top.

