What is 47 XYY Syndrome?

ben bunting BA(Hons) PgCert Sport & Exercise Nutriton  Written by Ben Bunting: BA(Hons), PGCert.


In this article we shall look at 47 XYY syndrome and how it may affect fertility in males. 

We shall cover the following points:

  • What's 47 XYY syndrome?
  • Frequency and causes
  • Symptoms
  • Male fertility
  • Diagnosis and treatment
  • Conclusion

47 XXY Syndrome

47 XYY is among the rare genetic order of men. It is a condition in which a male carries one extra copy of the Y chromosome.

It may also be referred to as Jacob's syndrome, XYY karyotype, or YY syndrome.

Some people describe such men as super-males. A case was reported of a 13 year old boy who was diagnosed due to his tall stature, but presented no further abnormal features. 

Such men might be unusually tall, often taller than 6 feet, but others may have many health issues and even differences have been reported of hormone production, testicle size, and fertility.

However, it is a complex disorder in way that it has a highly varied presentation.

In most, it causes very mild symptoms like a slow achievement of various childhood development milestones, a higher risk of brain disorders, mental problems, slow learning of motor skills, and poor development of language skills.

Nonetheless, it is worth understanding that many men living with the condition may have relatively good development and might not experience any significant issues during their lifetime.

It is because many bodies might be able to compensate for certain genetical deficiencies in different ways. It means that the condition remains undiagnosed in the vast majority of cases.

Frequency and causes of 47 XYY syndrome

The condition is classified as a rare disorder, and studies suggest that it affects about one in a thousand newborns. It means that though it is a rare disease, nonetheless, few million people are living with the condition globally.

It is not a hereditary disease. Thus, it is not something that one has inherited genetically from parents. Instead, researchers think that the cause of the disease is due to some error in the early sperm development. It means that some kind of mutation leads to the disorder.

Moreover, most men living with 47 XYY syndromes can expect to father a child and have a healthy child.

Signs and symptoms of 47 XYY syndrome

One of the reasons why this condition is so difficult to diagnose is that its signs and symptoms are quite mild in most cases, and thus even doctors fail to identify the disorder.

For example, height above six feet is common in the condition, but that is not a pathology. Additionally, it appears that such boys are more likely to develop severe acne.

Studies also show that men with 47 XYY appear to have lower IQ. Nevertheless, they only have a slightly lower IQ than an average adult, making it challenging to identify the condition.

Nonetheless, most of those living with the condition would have learning disabilities. Studies report that almost half of all those living with the condition have these problems. Similarly, there are higher chances of dyslexia.

Additionally, people living with the syndrome are at a greater risk of developing behavioral issues like hyperactivity, explosive temper, impulsive behavior, antisocial behavior, and other issues.

➡️READ: Natural treatments for male infertility

It is worth understanding that many of these signs develop at an early age, like a child might be slow in achieving development milestones like delayed walking and speaking. Similarly, teenagers may underperform at school and have various emotional issues.

Nonetheless, in most cases, their symptoms tend to be mild, thus hindering the timely diagnosis of the condition. Moreover, most of these symptoms are quite vague to make any conclusions.

47 XYY Syndrome Life Expectancy

Unfortunately for those living with the condition, a Danish study suggests that they have a life expectancy of around 10 years less than those without. 

It seems those with the condition expereince a higher rate of chronic diseases which can lead to death.

47 XYY syndrome associated with male infertility

What is 47 XYY Syndrome?

Now coming to the primary topic, does 47 XYY cause infertility? And what are its implications for those planning to have a child?

The good news is that 47 XYY syndrome does not seem to reduce male fertility in all cases.

Instead, it appears to increase the risk of infertility. As such, there are many reported cases of infertility in men living with 47 XYY. 

A study published in 2020 suggests that most men with the condition are "azoospermic or severely oligospermic". 

Alternatively, some may have hypogonadism which can affect fertility markers in men. You can read a bit more about low testosterone, here.

Moreover, even in those living with the condition and diagnosed with infertility, the problem may be treatable.

Nonetheless, it appears that most of those living with 47 XYY can father a child. While a significant number may need medical help, nevertheless, it is something that specialists can help overcome.

Moreover, it is not a condition that is passed to a child, and thus those treated for infertility can still expect to have a normal child.

Nonetheless, doctors would find it difficult to diagnose the condition solely based on symptoms.

Additionally, it is worth noticing that many men living with a condition may not have any issues related to fertility, and thus they remain undiagnosed with the condition.

There are no studies comparing the incidence of infertility in those living with 47 XYY syndromes and those with normal chromosome counts. However, it appears that 47 XYY is a minor risk factor, nonetheless, a relevant one.

Diagnosis & treatment options for 47 XYY syndrome

When it comes to the diagnosis of the condition, a detailed history of the patient may suggest the presence of the condition.

However, signs and symptoms cannot confirm the diagnosis. Thus, doctors would often order a range of diagnostic tests, including genetic testing, ultimately establishing the diagnosis.

Treatment of the condition would often depend on the predominant signs of the disease conditions.

For example, some teenagers would need behavioral therapy and other assistance in learning. The same is valid for adults, and they might need speech therapy, occupation therapy, education therapy, and so on.

When it comes to managing infertility in those diagnosed with the condition, the treatment is non-specific, as no medication can reverse the chromosome condition.

Instead, doctors would try to correct the pathological changes by using hormone therapy and various treatments to boost sperm count and motility. Additionally, specialists may suggest lifestyle interventions and supplements.

Like infertility due to other causes, treatment of infertility related to 47 XYY would be prolonged, and there are good chances that doctors might be able to treat infertility (not the syndrome) in many cases.


47 XYY syndrome is when a person carries an additional copy of genes. It is not a hereditary condtion passed through genetics, but may be caused by sperm irregularities during conception of the child. 

More often than not the symptoms can go unnoticed as they do not particularly stand out amongst other behavioral and physical changes within a childs peers. 

However, while those with 47 XYY can father children, there's a elevated risk of some with the condition to be infertile. In such cases, if the infertility is diagnosed, it may be treatable. 

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