← Go back

Many individuals will go through life not knowing they have XYY, also known as Jacobs syndrome, in fact it is believed that only 12% of males are diagnosed. A diagnosis of XYY in adults is often not common and often overlooked, since there is often no medical reason to test for XYY syndrome.

Although if an adult is diagnosed the time of receiving a diagnosis can be a completely overwhelming and confronting time with an array of emotions being experienced. For many adults the initial diagnoses are very impactful and life changing.

Being diagnosed with XYY can come as an enormous shock. It’s normal for individuals to experience a large range of emotions in the wake of such a diagnosis. Distress, devastation, fear and despair are extremely common following such a diagnosis. Research indicates that people who are experiencing several stressful life events before a diagnosis, and those with a history of depression, may be at particular risk of psychological distress when they learn they have a long-term condition. However, even people with relatively few stresses in life can be completely shaken by a new diagnosis and find it difficult to cope.

Grief is another common reaction to receiving a diagnosis. The individual may experience various stages of grief including denial, bargaining, anger and sadness. They may feel they’re on a roller coaster of emotion — accepting one day, and angry the next. It may be helpful for individuals to know that these feelings are normal, and will likely ease with time, support and more information. Many individuals with the right support can learn to manage these feelings and to live a fulfilling life.

For some individuals receiving a diagnosis of XYY as an adult can also be a time of relief with some individuals describing it as a ‘lightbulb moment’ where they finally understand why they feel the way they do. It may also help explain certain challenges they have had throughout life and why they may have struggled through school, find social situations at times challenging, have certain health issues and many other things. Many individuals are often misdiagnosed with autism or learning challenges prior to getting a XYY diagnoses, for some this has been an ongoing battle to receive the correct diagnosis. Once the correct diagnoses are made it often allows for targeted and individualised treatment options to be discussed and implemented.

An official diagnosis of XYY can help individuals answer a lot of questions they might have about themselves. It can also help (if they wish to disclose their diagnosis), those around them such as family, friends or employers, to understand the difficulties they may be experiencing and how they can make things a little easier. Many workplaces can modify or set up tools to help individuals in the workplace to become more productive and satisfied in their chosen careers.

Potential signs and symptoms and health risks that may be experienced.

It is important for adults to know that XYY is a spectrum and therefore everyone is affected in different ways and to varying degrees. The list of signs and symptoms for XYY is long and can overwhelm people but individuals will certainly not experience all the signs and symptoms, but MAY have some of the following signs and symptoms:

  • Hypotonia (low muscle tone)
  • Tiredness and fatigue
  • Taller than average height
  • Poor short-term memory
  • Poor concentration, ADHD is very common
  • Clinodactyly: Curved pinky finger
  • Speech and language delays
  • Learning difficulties usually associated with spelling, reading and writing, often with a diagnosis of dyslexia
  • Lack of co-ordination (dyspraxia)
  • Difficulty expressing themselves
  • Difficulties processing information – especially verbal instructions
  • Poor social development
  • Autistic tendencies, although mild
  • Display challenging behaviours, such as; an explosive temper, hyperactivity, impulsivity, defiant actions, emotional difficulties, or in some cases, antisocial behaviour
  • Sadness, lowered mood or depression and anxiety
  • Poor communication and social skills
  • Hand tremor
  • Pes plantus (flat feet)
  • Cystic acne in adolescence

Who should be involved in the care of an adult with Klinefelter syndrome/XXY?

Knowing, even with a diagnosis as an adult, opens the door to appropriate treatment, services and supports available, some of which the individual may not even know about. Finding a good GP that can do regular holistic health checks is very important. It is ideal that the GP knows about the other potential health implications that can be associated with XYY as they will need to do or order the appropriate health checks. If the GP doesn’t have a broad knowledge base on XYY and the associated co-morbidities, they should be referred to our website and look under the health professionals tab to gain further information, this will allow them to carry out and order the right health checks and tests.

Other health professionals that may need to be involved in the health care team of XYY individuals are:

  • Psychologist
  • Speech pathologist
  • Occupational therapist
  • Behavioural therapist


Treatment options available in adults with XYY

Some days individuals may be tempted to pretend they never received a diagnosis. However, facing their diagnosis head on is the best way to cope according to some research around adults receiving a diagnosis of a life-long disorder/syndrome/condition. Mental health and wellbeing are the number one priority post diagnosis and strategies should be implemented to help decrease any mental health impacts. Genetic counsellors, counsellors or psychologists can be fantastic and are much needed support that can help an individual implement the right tools to deal with and cope, although they must be the right fit for the person. Utilising a mental health plan through a GP helps to greatly minimise the costs associated with this.

An individual newly diagnosed adult with XYY should have a thorough health check-up including physical examination, blood tests and potentially bone scans. With ongoing support from health professionals and the best individualised treatment regime, this will all help make the day-to-day that bit easier and help minimise any associated medical conditions and ensure that individuals with a new diagnosis of XYY feel well supported.

Some individuals may have experienced lifelong challenges of speech and language delays or fine motor challenges, it is never too late to engage with a speech therapist or occupational therapist.

How can an individual actively face their new diagnosis?

A good place to start is by an individual writing down all their questions and taking them to a Genetics Counsellor or GP knowledgeable on XYY to discuss. Asking support groups important questions to ask is also helpful. Asking their doctor what specific steps they can take to optimise their health and mental wellbeing is very important. Accurate knowledge can help an individual feel empowered and ensure any potential health risks are detected, treated and minimised.

Finding other people who are going through the same thing can help individuals know the way they are feeling and coping with it all is very normal. Several in the AXYS community have been through this journey and can share their experiences. Working together through this time of overwhelming emotions often helps individuals with a new diagnosis of XYY move forward in a more positive light.Adults with XYY can also look at trying to manage the elements in their life that are within their control. They may not be able to control certain aspects of their newly found extra Y, but they can choose to eat healthy meals, investigate strategies to help with mental health, take medications as prescribed (if needed) and spend less time with people who aren’t supportive.

Additional Resources

Presentation AXYS Conference 2018 – Endocrine Care of Men with Klinefelter Syndrome. By Dr Stella Sarlos

AXYS 2018 conference presentation by an Endocrinologist on the different types of testosterone available in Australia and who they work.

Submission to the Australian Human Rights Commission

Protecting the human rights of people born with variations in sex characteristics in the context of medical interventions.

Tremor and Klinefelter’s Syndrome

Klinefelter syndrome (KS) has been associated with tremor, but reports on tremor phenomenology and treatment are limited.

Autism Spectrum Disorder in Males with Sex Chromosome Aneuploidy: XXY/Klinefelter syndrome, XYY, and XXYY

Neurodevelopmental concerns in males with sex chromosome aneuploidy (SCA) (XXY/Klinefelter syndrome, XYY, and XXYY) include many symptoms seen in autism spectrum disorder (ASD), such as speech-language impairment, verbal cognitive deficits, and social difficulties.

The Social Behavioral Phenotype in Boys and Girls with an Extra X Chromosome (Klinefelter Syndrome and Trisomy X): A Comparison with Autism Spectrum Disorder

The present study aimed to gain more insight in the social behavioral phenotype, and related autistic symptomatology, of children with an extra X chromosome in comparison to children with ASD.

Social Function in Multiple X and Y Chromosome Disorders: XXY, XYY, XXYY, XXXY

Studies on males with 47,XXY have revealed unique behavioral and social profiles with possible vulnerability to autistic traits. The prevalence of males with more than one extra sex chromosome (e.g., 48,XXYY and 48,XXXY) and an additional Y (e.g., 47,XYY) is less common, but it is important to understand their social functioning as it provides insight into treatment implications.

Load More

AXYS are here to provide support, guidance, information and are here
to help individuals link into the right health professionals.