These reference ranges are from Lab Corp: male, age 2-10: 0-0.5, age 11-20: 0.5-5.3. BUT Tanner Stage 1 is 0-3.6, stage 2: 0.3-4.8. The units are mIU/mL. According to this your son fits into Tanner stages 1 and 2. I don’t know why there is an overlap, maybe there is a decimal misplaced, but I’m sure I copied it right.

According to an article on precocious puberty at eMedcine.com, a LH level greater than 0.3 is considered pubertal; however, it also said that a testosterone level greater than 30 is pubertal.

Sorry this info is confusing and not of much help. I guess you need to keep a close eye on him for symptoms.