My 15 Yr. Old Was Diagnosed With Premature Puberty Years

My 15 yr. old was diagnosed with premature puberty years ago. He had pubic hair at age 2. He is small, has osteopenia, and other heath issues. Recently he had LH and FSH labs come back very elevated. His testosterone is low normal. All the normal symptoms for pre puberty did not exist (over weight, large & dense bones, large testicles, etc.) I want info. before I go into his appointment and the more I read, the more confused I get. Could he have primary testicular failure now after years of early puberty? Should I ask about anything specific?