THIRD EDITION
Factsheet
Condition:
47,XYY
Inheritance:
Chromosomal
Genetic Etiology:
47,XYY karyotype due to nondisjunction
Frequency:
Approximately 1:1,000 liveborn males
Clinical features:
Individuals with XYY have a male phenotype and are fertile. They tend to have learning disabilities and behavioral problems. Many have relatively tall stature.
Management:
Anticipatory guidance and support for learning disabilities.
Genetic counseling:
Recurrence is rare and can be detected by prenatal chromosomal analysis. Although males with XYY are fertile, transmission of XXY or XYY is rare.