My son has always been petite - short & thin. Some is hereditary - I am 5ft 4in & his natural father is the same or less. DJ is now 4ft 11.5in at the age of 14yrs. He had a growth spurt of 1.5in from age 13-13.5, and another of 2in from age 13.5-14. He just started puberty, his meds were increased on his last visit, he had a bone age done (we'll get the results the end of May).