Abstract
Objective: Report a case of primary amenorrhea, the ambulatory investigation about the condition, and discuss the genetic and endocrinological changes associated. Case details: A 16 years old female patient was referred to the gynecology endocrinological ambulatory due to an absence of menarche and incomplete secondary sex characteristics development. On the physical exam breast bud noted at the left and absent on the right side, sparse axillary and vaginal hair, Tanner M1P1. The laboratory research started with hormonal dosages and ultrasound images suggestive of ovarian insufficiency, diagnosis hipoteses then confirmed by karyotyping wich also showed gonadal dysgenesis. Then it was started estrogen hormone therapy and attendance to evaluate the therapy response and some complementary exames. Final considerations: Hypongonadis hypergonadotrofic as result of genetic changes in the X cromossome (pseudo isodicentric) were responsible for the primary amenorrhea and the incomplete secondary sex characteristics development. The biological, psychological and social consequences demand a therapeutic approach and a medical follow-up due to the possible clinical ways that this condition can advance.