Does treatment for klinefelter syndrome increase penis&testicle size? ive been told i may have it and my penis+testicals never grew during puberty

No: The genitals are relatively small with average penis size about an inch in resting length. Testis are also small & by adulthood make about half the usual amount of testosterone. The fragile X syndrome features enlarged testis in older kids/adults.

One should not wait: A teen guy should not be in the "I may have" Klinefelter syndrome situation, but instead should be getting diagnosed, by seeing his pediatrician or adolescent medicine doctor, who can order a chromosome analysis at the lab. Regardless of the test result, a pediatric endocrinologist can assess the delay or lack of puberty, and do treatment if available.