The most common cause of short stature is –
Constitutional delay in growth

This is significant cause of short stature in mid childhood period but the ultimate height is normal.
Their birth weight and height are normal.
Strong family history of parents having short stature in childhood with delay in onset of puberty is usually present.
The average growth velocity is normal and ultimate growth potential is adequate.
The bone age is less than chronological age.
Upper segment and lower segement ratio is normal.
Growth hormone and gonadotropin level after puberty are within normal range.
No treatment is required. The parents need to be reasured.
Constitutional
Systemic diseases
Hypothyroidism
Growth hormone deficiency