Information for Professionals

Mental Health
Speech, Physical and Occupational Therapists


Males with XXYY Syndrome are often diagnosed with other medical conditions or syndromes (or they may appear to have these conditions) before the XXYY diagnosis is made. These include:

  • Asperger Syndrome & Autism
  • ADD
  • Pervasive Developmental Disorder (PDD/NOS)
  • Sensory Integration Dysfunction
  • Hypotonia
  • Developmental Disability & Delay
  • Fragile X Syndrome
  • Epilepsy
  • Prader-Willi Syndrome
  • Speech Delays
  • Heart Problems
  • Hand tremors
  • Gynecomastia

Because many medical professionals have never had a patient with XXYY, it can be difficult to identify them.  We have published this document (link below) to help you to identify potential XXYY patients.  We created this booklet especially for outreach to Autism and ADHD groups and parents of children with those conditions because of the high rate of these two conditions in XXYY.

How to Identify XXYY

We also ask that you refer families to us.

Additionally, please note that older medical information on XXYY Syndrome is very limited and often out-dated. Males with XXYY are NOT necessarily violent. Such studies were conducted in prisons. Subjects did not have the benefit of correct diagnosis and treatment. Males with XXYY most likely DO need hormone replacement therapy. HRT does not make them aggressive. In fact, the opposite is true.

Mental Health

Mental Health professionals are in a unique position to assist in identifying males with XXYY Syndrome. If you see a patient with the following characteristics, coupled with other medical and learning problems or characteristics listed on this site, please refer him to his primary care physician and ask for genetic testing:

  • Moodiness
  • Bi-Polar disorder
  • Frustration
  • Outbursts
  • Difficulties in social situations
  • Extraordinary imagination
  • Difficulty telling the truth

Males with XXYY Syndrome often have unusual reactions to medications. Parents have found that ADD medications used at high doses can positively change behavior along with helping with attentional problems. Other medications for mood stabilization, etc., can seem to work for a while but then make matters worse. We encourage parents to keep written logs of changes in behavior of any kind after beginning medication treatments.


Males with XXYY Syndrome have unique and very prominent dental problems. Look for:

  • Taurodontism
  • Missing adult teeth
  • Poor enamel
  • Poor dental hygiene


Teachers are an extremely important piece of the XXYY puzzle. Males with XXYY are visual learners. They often hide in small places (under the desk, for example) because of sensory overload. Because of hand tremors, they may have significant difficulties with writing. Behavior outbursts may also happen.
The XXYY Project will be working on developing Individual Education Plans in the future. If you are a special education teacher and would like to contribute to the project, please contact us.

Speech, Physical and Occupational Therapists

Therapists, especially speech therapists, are often the first to see a male with XXYY Syndrome since speech delay is one of the first symptoms to become apparant. Some parents have found the use of sign language when a child is young seems to reduce frustration considerably. Because of low muscle tone, males with XXYY Syndrome need strengthening exercises for all muscles. A plan that includes all three therapies is the best possible assistance that can be given to a male with XXYY Syndrome at an early age. Occupational therapy is very valuable and if it can be done in conjunction with some training for the classroom teacher, it is most beneficial.

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