Short Stature Idiopathic Short Stature Height greater than two standard deviations below the mean for the age and sex of the reference population. C1740819 Idiopathic Short Stature ISS NICHD Height less than two standard deviations below the mean for the age and sex of the reference population for the age and sex of the individual for which no underlying cause can be identified. Idiopathic Short Stature Finding C118689