What is it?

Jacobs Syndrome, also known as XYY syndrome, is a genetic condition that occurs when a male has an extra Y chromosome. This condition is usually not inherited and occurs spontaneously during sperm or egg cell formation.

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Signs & symptoms

Many males with Jacobs syndrome may not have any noticeable symptoms or may have only mild symptoms. However, some individuals may have physical and developmental differences, such as increased height, delayed speech and language development, learning difficulties, and attention deficit hyperactivity disorder (ADHD). In rare cases, Jacobs syndrome may be associated with more severe medical issues, such as seizures or behavioral disorders.


Diagnosis of Jacobs syndrome typically involves genetic testing to confirm the presence of an extra Y chromosome. This may be done prenatally or after birth through blood testing.


Treatment of Jacobs syndrome focuses on managing any associated symptoms or medical issues. For example, speech therapy or educational interventions may be recommended for individuals with delayed speech and language development or learning difficulties. Behavioral therapy or medication may be recommended for individuals with ADHD or behavioral disorders. In rare cases, surgery may be necessary to address medical issues, such as hernias.

☝️ This is not a substitute for professional medical advice. Please consult with your physician before making any medical decision.

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