Hypogonadism

Definition
Delayed puberty (pubertas tarda) is an absence of breast development in girls after 13 years of age or prepubertal testicular size in boys after 14 years of age.

Classification

 * 1) functional hypogonadotropic hypogonadism – a transient disorder in which there is a delay in sexual development due to an imbalance of energy intake and expenditure (excessive exercise, malnutrition, inflammatory bowel disease (IBD), chronic lung disease, endocrinopathy); clinic : puberty delay, growth retardation and weight failure;
 * 2) permanentní hypogonadotropic hypogonadism – arises from a number of congenital and acquired causes; acquired causes are, for example, inflammations, tumors and injuries of the CNS and hypothalamus or their iatrogenic damage;  congenital causes are eg Kallman's syndrome (a disorder of formation and migration of neurons forming GnRH and agenesis of bulbus olfactorius - hypogonadism + anosmia), Prader-Willi syndrome (defect of chromosome 15 with hypothalamic involvement - (hyperphagia, hypogonadism, growth retardation), Laurence-Moon-Biedl syndrome (hypogonadism, PMR, polydactyly, obesity, short stature) gonadoliberin or LH / FSH receptor mutations;
 * 3) hypergonadotropic hypogonadism – the causes are genetic syndromes – Klinefelter's syndrome (extra X chromosome in men – gynecomastia, eunuchoid habitus, hypogonadism), Turner syndrome (structural or numerical abnormality of the X chromosome in women – short stature, gonadal dysgenesis, congenital defects), congenital errors of metabolism – galactosemia, mucopolysaccharidosis, cryptorchidism (testicular descent disorder), testicular dysgenesis/agenesis, testicular injury/torsion, infections (parotitis), autoimmune disorders (AI oophoritis/orchitis), iatrogenic testicular involvement in cancer treatment;
 * 4) other causes – androgen production defect, androgen resistance.

Diagnosis
A comprehensive examination of the child; anamnesis + physical examination; laboratory: LH / FSH, testosterone, estradiol, prolactin, TSH/fT4, iontogram, urea, creatinine, liver enzymes, IGF-I, growth hormone; further examination: exclusion of AI disease; genetic testing; imaging methods (USG - ovaries in girls, brain MRI in central hypogonadism); stimulation tests (GnRH stimulation test – demonstration of central hypogonadism, hCG stimulation test –stimulation; gonads and determination of hormone levels at low gonadotropin levels).

Treatment
In functional disorders, treatment of the underlying disease + induction of puberty by testosterone in boys, transient administration of hCG, in girls transient administration of estrogens; permanent hypogonadism - sex hormone replacement therapy (we start from small doses which we gradually increase). In girls, we start estrogen therapy a and after 2 years we add progestogens to induce an artificial menstrual cycle. We then proceed with cyclic administration of both hormones to achieve feminization. We administer testosterone to the boys.