Adult Onset Isolated Hypogonadotropic Hypogonadism: A Cause of Secondary Amenorrhea

A 23-year-old African American female presented with secondary amenorrhea, hot flashes, sweating, intentional weight loss, hair loss, and nipple discharge but no anosmia. Her medical history included asthma, anxiety, and obstructive sleep apnea, and she had a history of using oral contraceptives and cannabis. Physical examination showed normal secondary sexual characteristics and no thyroid or adrenal abnormalities. Laboratory tests revealed undetectable gonadotropins, low estradiol and testosterone levels, but normal thyroid function, cortisol, and prolactin levels. An MRI showed a normal brain and pituitary gland, and a pelvic ultrasound showed normal ovaries with multiple follicles. The diagnosis was adult-onset isolated hypogonadotropic hypogonadism (IHH), a rare genetic disorder in females characterized by defective production or action of gonadotropin-releasing hormone (GnRH). The patient was treated with estradiol patches and progesterone. IHH has a wide range of clinical presentations and is treated with hormones to induce puberty, maintain sexual maturation, and restore fertility.