What is it?

In simplistic terms Klinefelter’s Syndrome (KS) is a genetic condition where a male is born with an extra X chromosome. This extra X chromosome can cause a very wide range of serious health conditions and presents a male with very low or no testosterone.

KS is found in 1 in 600 male births. Typically, males are born with one X and one Y chromosome (XY) and females are born with two X chromosomes (XX). KS males are born with two X chromosomes and one Y chromosome (XXY or 47 XXY). There are other variations of chromosome syndromes including 48 XXXY & 49 XXXXY, where facial deformity, eyes further apart, hooded eyelids, undescended penis and testicles are the norm. 48 XXXY and 49 XXXXY are far less common with 1 out of 85,000 to 100,000 male births are affected.

Although KS is often described as 47 XXY and vice versa, the two conditions are not interchangeable. Some males are born with KS yet are 46 XY; some females are born XXY yet can’t be KS as the symptoms of KS wouldn’t apply to them.

KS is also a spectrum disorder as it has overlapping symptoms that relate to Autism, Asperger and Attention Deficit Hyperactivity Disorder (ADHD). In fact, up to 25% of males diagnosed with KS have autism / Asperger.

Diagnosis / My Diagnosis

I was diagnosed with KS / 47 XXY in 2015, at the age of 49. I was initially diagnosed by an endocrinologist at my local hospital, which was then officially confirmed at Guys Hospital, London a couple of months later. In 2018, after 18 months of waiting I was officially diagnosed with Asperger.

Being diagnosed at such a late stage in my life is not untypical, in fact many males live a full and productive life without ever knowing they had KS. Due to KS being a spectrum disorder, symptoms vary from person to person, making a specific diagnosis difficult. The other difficulty is that GP’s and consultants, even those who specialise in hormone issues are not sufficiently trained to diagnose or treat KS. The other issue is because KS involves conditions of an intimate nature, many men are unwilling to come forward for diagnosis or even admit there is something wrong.

5 years prior to getting diagnosed I was running my own very successful supplement company; I was awake 18 hours a day, weight training, working, eating right and then suddenly out of the blue I started falling asleep at the computer at 10pm, found that I had become lack-lustre, etc. Thinking I had something like cancer, I went to my GP, who did some blood tests and reported back that I had low testosterone. The rest is history.

It took something like this for me to get diagnosed but prior to this, I had no clue. It was only when I was diagnosed with both KS and Asperger that everything fitted into place regarding my childhood, the dislike of team sports, unable to make friends, the inability to stay in a job more than 3 years – for which I couldn’t see a problem but everybody else could.

If it is suspected that you have KS then your GP should arrange a blood test. Some GPs are more pro-active than others, but the most basic blood tests should be Luteinising Hormone (LH), Follicle Stimulating Hormone (FSH), Sex Hormone Binding Globulin (SHBG) and Testosterone (T). My GP, when I was first diagnosed & even now gets bloods done for oestrogen, glucose, full blood count and haemoglobin.

LH, FSH, SHBG should be raised and T should be low. The normal range is between 9.9 & 28.5 nmol/L. On first diagnosis my level was 6.2 nmol/L. High LH, FSH, SHBG levels and low T levels mean that your testes are producing little or no testosterone, which is called primary hypogonadism. There is another version of hypogonadism called secondary hypogonadism which is caused by other issues such as testicular cancer.


Common symptoms of Klinefelter’s Syndrome, include (not everybody suffers from these symptoms) and this is not an exhaustive list:

  • small penis and small, firm testicles (I have a larger than average penis & my testicles were around 10ml when diagnosed, now smaller due to atrophy);
  • little or no sperm production (I have ejaculate but no sperm);
  • enlarged breasts, gynaecomastia;
  • very little hair on face, armpits, pubic area and body (I could always grow a full goatee & beard pre-diagnosis and had normal pubic hair, yet no chest, back or body hair);
  • increased height (I am 6ft 4″, I am taller than all of my family by a good foot (men));
  • long legs & short trunk;
  • lack of muscle tone and strength (sarcopenic obesity or skinny fat);
  • lack of energy;
  • low sex drive (even on TRT my sex drive is low to non-existent);
  • increased belly fat (I have a greater amount of stomach and truncal fat);
  • problems reading, writing and communicating (no issues with reading and writing, communication is an issue but I also have Aspergers as well);
  • infertility;
  • anxiety and depression (used to suffer from anxiety & depression. TRT helps with this);
  • problems interacting socially (have had this all my life, but it’s also an Aspergers trait);
  • metabolic disorders (such as diabetes, osteoporosis, rheumatoid arthritis, IBS).


Klinefelter’s Syndrome is typically treated using testosterone replacement therapy or TRT for short. People with mild symptoms don’t require any treatment, whereas those with more concerning issues require treatment. Not everybody with KS has testosterone though, some have HCG on its own while others have oestrogen or HRT.

TRT administered around the time of puberty triggers normal growth which would have otherwise been delayed or not happen at all. These include – deepening of the voice, facial and body hair, increased muscle strength, penis growth and bone strengthening.

See https://www.living-with.co.uk/testosterone-replacement-therapy/ regarding the different versions of TRT, with more detailed descriptions of each version on this website.


KS has always been known as a syndrome where fathering children is impossible. However, it is now known that if sperm can be found, then it can be extracted via a procedure called intra cytoplasmic sperm extraction with intra cytoplasmic sperm injection (TESE-ICSI).

There are other versions of sperm extraction including Testicular Sperm Extraction (TESE), Testicular Sperm Extraction by Aspiration (TESA) & Microsurgical Testicular Sperm Extraction (Micro-TESE).

Living with … KS

As a teen I endured constant bullying because I was different – taller than other kids my age, skinnier, didn’t want to join in team sports and was shy. These differences are pretty much typical of KS guys even into later life. Boys, teens are going to feel self-conscious or even embarrassed that they are not developing like their peers. Men diagnosed as children or later in life may get upset knowing they can’t father children.

Counselling can help to manage depression, low self-esteem or any other emotional issues that can arise due to KS. Support groups are a good outlet for both KS males and their parents and in the UK the https://www.ksa-uk.net/ website is an excellent source of information for all parties, including medical professionals.

Children with KS may require extra help in school. KS is defined as a disability and as such schools have special programmes aimed at children with disabilities. Many boys & men have trouble socially interacting so finding an occupational or behavioural therapist can help them learn social skills.

I wasn’t diagnosed until I was 49 so the negative effects of both KS and Asperger that I have, meant that I had to learn how to socially interact myself. Even after multiple years of counselling for the bullying, both KS and Asperger was never picked up. As a person, I know how to behave in public and in intimate company due to learned behaviour. Some experts will say that this is an act, that you don’t really feel the emotions, you’re just playing a role. I disagree. However, I am a very touchy-feely person but I think that stems from my childhood where emotional love was limited.


There are complications to watch for with KS, regardless of whether you’re on treatment or not. These include (but are not limited to):

  • breast cancer, prostate cancer;
  • lung disease, including bronchitis and COPD;
  • osteopenia and osteoporosis;
  • heart and blood vessel disease;
  • varicose veins;
  • diabetes;
  • hypothyroidism;
  • autoimmune disease such as rheumatoid arthritis, lupus, Sjogren syndrome;
  • rare tumours called extra gonadal germ cell tumour.

What now?

In the first instance, if you suspect that you or your child has KS then an appointment with your GP is required. They will arrange for blood tests to be carried out. If like me, my blood test results showed low testosterone and I was referred to an endocrinologist at my local hospital, where she diagnosed KS. I was started on treatment there and then in the form of gel-based testosterone. I was then referred to Guys Hospital in London where they tested me to verify definitively that I had KS / 47 XXY.

After that I researched everything KS, which is why after 5 years this website exists as I wanted to share my research and findings with everyone. With regards to support, I found it difficult to find a counsellor that even knew about KS & a long-time friend who is a counsellor, actually said to me, “well if you’re on testosterone, you’ll be getting roid rage” – which is simply not the case.

On the most popular social media platforms there are multiple groups that specialise in KS. The people range from newbies right the way up to experts in KS. People are very welcoming; there are some arseholes with their own agendas (such as causing arguments for the sake of it) and people are happy to chat, share information & help you out, which may alleviate your worries and issues. In fact, you’ll more than likely find that the information garnered from the groups and the research that you will do yourself are far more useful & informative than anything an endocrinologist will ever tell you.