Chapter 161 Amenorrhea: Primary
INTRODUCTION
ETIOLOGY AND PATHOGENESIS
Causes: Gonadal abnormalities (failure, 60% of patients)—autoimmune ovarian failure (Blizzard syndrome), gonadal dysgenesis, pure gonadal dysgenesis, 45,XO (Turner’s syndrome), 46,XY gonadal dysgenesis (Swyer syndrome), 46,XX q5 X chromosome long-arm deletion, mixed or mosaic, follicular depletion, autoimmune disease, infection (e.g., mumps), infiltrative disease processes (e.g., tuberculosis, galactosemia), iatrogenic ovarian failure (e.g., alkylating chemotherapy, irradiation), ovarian insensitivity syndrome (resistant ovary [Savage’s] syndrome), 17α-hydroxylase deficiency, chronic anovulation of pubertal onset. Extragonadal anomalies (40%)—congenital absence of uterus and vagina (15%) (Müllerian agenesis), constitutional delay, imperforate hymen, male pseudohermaphroditism (testicular feminization syndrome), pituitary–hypothalamic dysfunction, transverse vaginal septum.
