X-linked adrenal hypoplasia congenita is a disorder that is noticeable from birth (congenital) and affects the development of the adrenal glands, which are hormone-producing (endocrine) organs (glands) located on top of each kidney. These glands produce a variety of hormones that regulate many essential functions in the body, such as response to stress.~One of the main signs of this disorder is adrenal insufficiency, which occurs when the adrenal glands do not produce enough hormones. Adrenal insufficiency typically begins in infancy or childhood and can cause vomiting, difficulty with feeding, dehydration, extremely low blood glucose (hypoglycemia), and shock. If untreated, these complications are often life-threatening.~Individuals with X-linked adrenal hypoplasia congenita may also have a shortage of male sex hormones, which leads to underdeveloped reproductive tissues, undescended testicles (cryptorchidism), delayed puberty, and an inability to father children (infertility). Together, these characteristics are known as hypogonadotropic hypogonadism.~The onset and severity of these signs and symptoms can vary, even among affected members of the same family.