XYY Syndrome Flashcards
A 12-year-old boy is referred for evaluation due to concerns about his academic performance and behavior at school. He has a history of mild delays in motor milestones and currently receives speech therapy for language difficulties. His parents report that he is taller than his peers. Physical examination reveals normal secondary sexual characteristics and no dysmorphic features. Laboratory results are unremarkable. Chromosomal analysis reveals a 47,XYY karyotype. Which of the following is the most likely explanation for this patient’s difficulties?
A) Low testosterone levels
B) Learning disabilities and behavioral challenges
C) Increased aggression due to an extra Y chromosome
D) Hypogonadism
E) Intellectual disability
Answer: Learning disabilities and behavioral challenges
Explanation: 47,XYY syndrome is characterized by tall stature and mild neurodevelopmental and behavioral challenges. While individuals typically have normal fertility and secondary sexual development, they are at increased risk for learning disabilities, particularly in language and reading, as well as behavioral issues like ADHD and social immaturity. Contrary to misconceptions, increased aggression is not a common feature. Testosterone levels and sexual development are normal, and intellectual disability is rare.
Incorrect Answers:
A) Low testosterone levels: Testosterone levels are typically normal in 47,XYY syndrome.
C) Increased aggression due to an extra Y chromosome: Aggression is not a hallmark feature of 47,XYY syndrome.
D) Hypogonadism: This condition is not associated with hypogonadism.
E) Intellectual disability: Intellectual disability is uncommon, though learning challenges are prevalent.
What is the karyotype associated with 47,XYY syndrome?
47,XYY
What is the phenotype associated with 47,XYY syndrome?
- Male phenotype (patients often remain undiagnosed).
-Tall stature.
- May manifest with severe acne.
- Normal fertility and pubertal development.
What is the most common mechanism leading to 47,XYY syndrome?
Nondisjunction during paternal meiosis II
What is the incidence of 47,XYY syndrome in live male births?
Approximately 1 in 1,000 male births
Name three common neurodevelopmental challenges in individuals with 47,XYY syndrome.
Learning disabilities, delayed motor skills (ASD), mild hypotonia.
What behavioral challenges are associated with 47,XYY syndrome?
ADHD, impulsivity, difficulty with social interactions.
Is fertility typically affected in 47,XYY syndrome?
No, most individuals have normal fertility and sexual development.
What are common diagnostic methods for 47,XYY syndrome?
Prenatal diagnosis via amniocentesis or chorionic villus sampling.
Postnatal diagnosis through karyotyping.
What are the primary goals of educational support in 47,XYY syndrome?
Early intervention for learning disabilities; individualized education plans (IEPs) for academic challenges.
What behavioral therapy is recommended for individuals with 47,XYY syndrome?
Behavioral therapy for ADHD and social difficulties.
What is the general prognosis for individuals with 47,XYY syndrome?
Generally favorable, with most individuals leading normal lives; early intervention improves outcomes.
