In Klinefelter's syndrome, which of the following is not a typical physical characteristic?

In Klinefelter's syndrome, the condition typically presents with a range of physical characteristics resulting from the presence of an extra X chromosome in males. One of the hallmark features of this syndrome includes gynecomastia, which is the development of breast tissue in males. This occurs due to hormonal imbalances that are common in individuals with Klinefelter's syndrome.

Long limbs are also characteristic, as individuals often have tall statures and legs that are disproportionately longer than average. Additionally, those with Klinefelter's syndrome frequently exhibit a lack of secondary sexual characteristics during puberty, which means they may experience underdeveloped facial and body hair along with small testes due to inadequate testosterone levels.

However, large testes are not a typical physical characteristic in Klinefelter's syndrome. In fact, individuals with this condition usually have small, firm testes, which is the opposite of large testes. This is an important aspect of diagnosing Klinefelter's syndrome, as the underdevelopment of the testes contributes to infertility and reduced secondary sexual characteristics.