What is this disease called?

• Jacob Syndrome
• XYY Syndrome
• XYY Karyotype
• YY Syndrome

The causes and inheritance:

Jacob's Syndrome is a random mix up or mutation during creation of genetic code. Most cases are not inherited; having Jacob’s syndrome does not make your children more likely to have it. The mutation can occur at any point during meiosis of sperm cells-- some cells can have the mutation while others don’t. The mutation is a form of nondisjunction.

Phenotypic Effects:

• Taller than average
• Weaker muscle tone
• Severe cystic acne during adolescence
• Fairly normal intelligence: on average IQ is 10 to 15 points lower than siblings
• Mild delays in reaching developmental milestones
• Speech delays and language problems are common
• Reading difficulties are common due to an increased incidence of dyslexia

Social Issues:

• Increased risk for behavioral issues and learning disabilities
• Thought that they were overly aggressive and lacked empathy but recent studies have proved that wrong
• Generally they lead full, healthy lives