Parents are often think that all KS/XXY youngsters will not complete puberty naturally.

Although this may be true for a minority, most will be fine. 

Many endocrinologists like to see a child around the age of 9, in order to let them become used to attending the hospital and to get to know their endocrinologist.

The age at which KS youngsters start puberty is the same as for other boys ie about 12 years of age. This is when the testicles begin to enlarge. Puberty then progresses normally for the first two years or so. After this the testicles may stop growing or shrink slightly and testosterone levels may not rise rapidly above the age of 14 as would be usual.

Unless puberty has been delayed, it is probably not necessary to do checks until mid-puberty – 14 or 15.

It is not usual to prescribe hormone replacement those under sixteen years of age. About half will not need testosterone treatment until much later. However, a low dose of testosterone treatment may be beneficial to those who are overweight or who are developing gynaecomastia.