Parameter | GnRH-dependent precocious puberty | GnRH-independent precocious puberty |
Nature of puberty | Isosexual | Isosexual or heterosexual |
Sequence of pubertal events | Similar to normal puberty | Disordered |
Height velocity | Increased. Normal if coexistent growth hormone deficiency | Increased. Decreased in hypothyroidism |
Cycles of breast growth and regression (girls) | Absent | May be present |
Testicular size (boys) | Symmetric increase appropriate for pubertal stage | Prepubertal/asymmetric increase/symmetric increase but small for pubertal stage |
GnRH stimulation test | Luteinising hormoneĀ (LH) peak in pubertal range | LH peak in prepubertal range |
Common aetiologies | Hypothalamic hamartoma, astrocytoma, previous encephalitis, radiation exposure, hydrocephalus | Congenital adrenal hyperplasia, adrenal neoplasm, hypothyroidism, McCune-Albright syndrome, familial testotoxicosis, exogenous sex steroid intake |