...research on the detailed patterns of physical development during puberty and the cut-off values and changes of hormones at the initiation of puberty and developmental maturation is rare. ...increased testosterone (T) level is usually concordant with changes in secondary sexual characteristics in boys. After 12 weeks of pump therapy, patients reported testicle and penis growth, especially testicle volume, which increased more significantly and earlier than penis size. ...beard or pubic hair appeared in 38.9% (7/18), and three patients reported initial seminal emission after 39 weeks. In Grinspon's study,5 there were no specific time points for children with pump treatment, whereas we performed LHRH stimulation tests in patients receiving pump therapy to determine the cut-off values of hormone levels at specific follow-up time points. ...this prospective study was able to determine more relevant LH ranges to determine the initiation and maturation of the hypothalamic-pituitary-gonadal (HPG) axis.