<prompt> Commonest cause of primary amenorrhea:Gonadal dysgenesisMullerian agenesisAndrogen insensitivity syndromeStein Levinthal syndrome  <response>: Ans. A. Gonadal dysgenesis.Gonadal dysgenesis does not equate with turners syndrome. There are many causes of gonadal dysgenesis in the female, most of which relate to abnormalities involving X chromosome e.g. Turner syndrome, turner mosaic, 46XY gonadal dysgenesis. 25 of girls with gonadal dysgenesis have 46XX karyotype. Turner syndrome is the most common form of gonadal dysgenesis 