219- What are the disorders associated with absence of mini-puberty?
Mini-puberty is absent in children with congenital hypogonadotropic hypogo-
nadism and complete androgen insensitivity syndrome; however, it is present in
children with partial androgen insensitivity syndrome. This underscores the
importance of androgens in priming of GnRH-gonadotropin axis for the onset
of mini-puberty. In addition, infants with CAH and androgen excess of any
etiology (e.g., congenital adrenocortical carcinoma) may not experience mini-
puberty because of suppression of gonadotropins by excess androgen.- What are the gender dimorphisms acquired during peripubertal period?
Negative feedback between most of the target glands and hypothalamic–pitu-
itary axis is usually established by 2–3 years of age. However, estrogen- mediated
positive feedback for LH in girls is acquired only during peripubertal period and
is responsible for initiation of ovulatory cycles. Further, the gender difference in
serum prolactin level, i.e., higher levels in women as compared to men, is also
acquired during peripubertal period consequent to estrogen production.- How to define hypogonadism?
Hypogonadism refers to a clinical syndrome characterized by impaired gonadal
function resulting in decreased gonadal steroidogenesis and/or gametogenesis.
However, in clinical practice, those with isolated germ cell dysfunction but with
normal gonadal steroidogenesis are not considered as having hypogonadism.
Similarly, a well-feminized female with normal circulating levels of estradiol,
but with chronic anovulation (e.g., polycystic ovarian disease), is not consid-
ered to have hypogonadism.- How to classify hypogonadism?
Hypogonadism is classified based on the site of primary defect in the hypotha-
lamic–pituitary–gonadal (HPG) axis. Disorders caused by abnormalities of
hypothalamus and pituitary gland are termed as hypogonadotropic hypogonad-
ism, whereas those with a primary defect at the level of gonads are termed as
hypergonadotropic hypogonadism (primary gonadal failure).- What are the causes of delayed puberty?
The most common cause of delayed puberty is CDGP, followed by hypogonado-
tropic hypogonadism and hypergonadotropic hypogonadism. The prevalence of
various causes of delayed puberty is summarized in the table given below.Disorders Boys Girls
CDGP 65 % 30 %
Hypogonadotropic hypogonadism
Functional 20 % 20 %
Permanent 10 % 20 %
Hypergonadotropic hypogonadism 5–10 % 25–30 %7 Delayed Puberty