Only 57.9 % of our girls with precocious puberty had a stimulated LH above 5.0 IU/L, and girls with premature thelarche in age group 1⁄2-3 years exhibited a stimulated LH comparable to the stimulated LH in the precocious puberty group in 5–7 year old girls. This evidence concerns the gene PLOD1 and precocious puberty.