Idiopathic Short Stature (ISS) is when a child is shorter than their peers for no known reason. This study aims to collect growth data from children with ISS. To join, children must be over 2 years and not older than 14 (girls) or 16 (boys). They should have a height Z-score of ≤ -2.25, which means they're shorter than most kids their age. Some participants might be receiving human Growth Hormone (hGH) treatment. A growth stimulation test should show a hormone level greater than 10 μg/L. Parents need to consent for their child's participation.

However, children with certain conditions causing short stature, like some diseases or genetic syndromes, cannot join unless their condition is controlled, as decided by a doctor. They also cannot join if they recently tried another experimental treatment.

Key Points:

• The study collects growth measurements over time.
• Participants must be between 2-14 years (girls) or 2-16 years (boys).
• Some medical conditions or recent experimental treatments may exclude participation.