Snapshot A 19-year-old female presents to the gynecologist for the first time. She reports that she has not started to menstruate. The OB/GYN notes that the patient is short-statured and has notably delayed breast development with webbing skin between the neck and shoulders. Introduction Genetic disorder caused by a missing X chromosome in females (45XO) Most common cause of primary amenorrhea (uterus present) Most patients are infertile ETIOLOGY Associated with greater risk for developing co-morbities including login to view 11 more bullets Presentation Symptoms login to view 3 more bullets Physical exam login to view 9 more bullets IMAGING Endoscopy login to view 1 more bullet STUDIES Buccal smear for absent Barr bodies is outdated diagnostic method Labs login to view 1 more bullet Karyotype analysis login to view 2 more bullets Fertility testing login to view 1 more bullet DIAGNOSIS Diagnosis is based primarily on physical exam and patient history Differential Down syndrome, polycystic ovarian disorder Treatment Prevention login to view 1 more bullet Medical management login to view 7 more bullets Complications Coarctation of the aorta, ovarian dysgenesis, GI telangiectasias Prognosis Good to very good with appropriate treatment Most patients live complete lives