Diagnosis in children

KS/XXY is difficult to recognise in children because the classic symptoms occur only after puberty – sparse body hair, lack of muscle etc.

However, there are still  many signs to watch out for:

Common symptoms

Common health issues

The condition is being picked up more often than in the past- although still not nearly often enough.

The KSA is working to raise the profile of the condition generally, but within the medical profession in particular. Please help us by telling your GP that KS/XXY isn’t rare. It affects about 1 in 600 males. Tell them that the KSA offers free membership to medical professionals.

Trigger times and signs for diagnosis

During pregnancy.
If screening was carried out for Down's Syndrome etc. the extra chromosome may be discovered.

KS/XXY babies often have uni- or bi-lateral cryptorchidism (undescended testicles). They may present as 'floppy' babies and have difficulty feeding due to poor muscle tone.

Currently, there is no ante-natal screening programme for KS/XXY

Pre-school, if the child has a language delay or disorder. This is the most common problem for children. Speech therapy can make a considerable difference. Because KS/XXY folk are usually visual thinkers, models, diagrams, charts and colours will make life easier.

During schooling, if the youngster is having difficulties either socially or academically.

Often youngsters become frustrated because they find it difficult to express themselves and have problems processing information.

Everything seems to take longer and they are often perceived as being stupid and lazy - when they know they are neither!

They are visual thinkers so models, diagrams, charts, colours and written instructions may make life easier.

Young adults are likely to become aware that their genital area is not developing in the same way as their peers.

There might be some breast development and puberty may be slightly delayed.

Social awkwardness may become a problem and they may find it more difficult to relate to their peers.

Libido may be low and various behaviour issues might become apparent as they struggle to 'fit in'.

They are often immature for their years and can be very vulnerable.

Many cases of KS/XXY are diagnosed following infertility investigations. This can be a very difficult time and often little support, or even information, is offered.

Parents 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/XXY 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.

Most KS/XXY youngsters complete puberty without assistance. 

Unless puberty has been delayed, it is usually 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.

If KS/XXY is suspected, a GP should arrange a genetic blood test which looks at the pattern of the chromosomes (karyotype). If positive, they may want a second test to check if all the cells are 47, XXY.

Sometimes only some cells contain the extra chromosome. This is known as a mosaic. This has a typical karyotype 46 XY/47 XXY. Symptoms may be even less obvious if there is a mosaic.