This men’s health condition isn’t rare, but it’s rarely diagnosed

6 min

Klinefelter syndrome refers to a collection of characteristics in males that are caused by having two or more X chromosomes. It’s the most common chromosomal disorder affecting men and it can have a range of physical, mental and social effects.

The number of males with Klinefelter syndrome is not known, but 1-2 in 1000 newborn baby boys are diagnosed with the condition.

If you’ve never heard of it, you’re certainly not alone. Its limited awareness amongst the public and health professionals is one of the reasons many men go undiagnosed throughout their life.

While there’s no cure for the condition, timely diagnosis and specialist management can significantly enhance the quality of life of those who have it. And a better understanding of men’s lived experience can help bust the misconceptions that make the condition hard to talk about.

Why Klinefelter syndrome isn’t being diagnosed

“Worldwide figures suggest that less than half of men with Klinefelter syndrome are ever diagnosed,”  

– Prof Rob McLachlan, Andrologist and Healthy Male Medical Director,

A number of factors contribute to the poor diagnostic rate of Klinefelter syndrome including low awareness, the hesitancy of men to seek medical attention and the variability of symptoms and their severity. 

“The fundamental point is that it’s not ‘one size fits all’, there are many different presentations and a range of impacts of this chromosome imbalance,”

“Some of them are so subtle that the men are never diagnosed throughout their life, and some who have got these more noticeable symptoms, such as childhood learning disability, are picked up very early.”

– Prof Rob McLachlan, Andrologist and Healthy Male Medical Director,

Symptoms of Klinefelter syndrome in childhood may include long legs and tall stature, and difficulties with speaking, learning, behaviour and socialising.

Adults with Klinefelter syndrome might notice reduced growth of the testes and penis, reduced facial and body hair growth, reduced muscle and bone development, and gynaecomastia.

Some men may experience all of these symptoms and some may relate to very few. Often men are diagnosed when they try to start a family as even for those with mild symptoms, most men with Klinefelter syndrome produce very few or no sperm and are infertile.

“We’ve made a particular focus over many years to educate doctors, both GPs and specialists, that men don’t always present as a typical textbook case,”

“It was taught in medical student books to be so obvious, it’s often quite subtle.”

– Prof Rob McLachlan, Andrologist and Healthy Male Medical Director,

After puberty, a genital examination is the most effective way to detect Klinefelter syndrome as virtually all have small testes in the 2-4 ml range (around the size of a grape) compared to normal >15ml.

This is very obvious on examination, but these aren’t often common practice and the opportunity is lost. It’s then diagnosed with a blood test that examines someone’s karyotype and confirms the presence of an extra X chromosome.

Why men with Klinefelter syndrome need to be diagnosed

“I had not heard of Klinefelter, but I’ve since learnt a lot more about it,”

“Being diagnosed made some things fall into place – why I’m as tall as I am, why I’ve always carried more weight around my hips, waist and chest, and why I often felt tired.”

– Geoff, 43, who was diagnosed after he and his wife were unable to conceive.

Klinefelter syndrome can impact the health and quality of life of men in a variety of ways.

Although the related issues sound severe and a quick Google search offers overwhelmingly negative information, an accurate diagnosis and ongoing specialist treatment managed by your doctor can help minimise the effects of the condition on your wellbeing and improve your quality of life.

“If you don’t have hormone therapy when you need it, and most men with Klinefelter syndrome do, you will have a life which is suboptimal, it’s not optimised by feelings of good health, muscle development, bone and muscle strength, and motivation,”

“The quality of life of men with Klinefelter who are picked up is almost always improved with androgen therapy after puberty and beyond and it’s lifelong.”

– Prof Rob McLachlan, Andrologist and Healthy Male Medical Director,

Geoff says treatment gave him a new lease on life.

“I have a lot more energy and I’m much more motivated to do things like exercise. It’s helped with my sex drive and muscle development, and it’s given me more confidence.”

For some men, a diagnosis can help them validate their experience, accept and understand their differences, connect with others, access resources and adapt to living with the condition.

“Thinking about childhood… the big thing is I had learning difficulties, so I now revert back to that and go, ‘Oh my God, that all makes sense now,’”

“It took me longer to learn things. I was in special academic groups. So that, for me, answers a lot.”

Seamus, 35

When Seamus was sexually active in his early 20s, he noticed his testes looked and felt different, and he dealt with fatigue and low sex drive as he got older. But it took over a decade to be diagnosed with Klinefelter syndrome with a further delay in treatment.

“Once they actually confirmed it was a bit devastating,”

“To be honest, I was quite depressed, and I went into a bit of a hole.”

– Seamus

However, after connecting with other men with Klinefelter syndrome, having the support of his mum who has a medical background, finding more answers and starting treatment, Seamus is ‘a totally different person’.

“I felt like I had to have a lot of personal growth,”

“I had a good support group as well and friends, even though friends didn’t understand it. No one understood it, but I knew I had the lifeline like Ryan [founder of Living with XXY] that I could comfortably talk about what we’re going through.”

– Seamus

Geoff says that although dealing with the diagnosis can be “pretty full on” it’s also important to discuss the positives of Klinefelter syndrome.

“We’re just as amazing as anyone else out there, and just happen to be born with an extra X chromosome,” he says. “Some of the positives I’ve discovered along the journey include that we’re talented with our hands and love to experiment with hands-on projects; we’re right-brained with many creative insights and expressions through art, photography and music; and we’re sensitive, emotional and compassionate, often putting others before ourselves.”

Although he struggled to discuss it with other people at first, Seamus is open about the condition now and can focus on the positives.

“Men are not comfortable talking about the issue and I think that’s why we need to bring that to the table,”

“I just think if you know that there’s something different, get out there and check it out, don’t hold back… you might not get those answers straight away, but do your research.”

– Seamus


Klinefelter syndrome

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