A 2-year-old boy is diagnosed with Down syndrome. What chromosomal changes may be the cause of this disease?

Answer options

1. Trisomy 13
2. Trisomy X
3. Trisomy 18
4. Trisomy 21
5. Monosomy X

Explanation

Down syndrome is a genetic disorder caused when abnormal cell division results in extra genetic material from chromosome 21. Patau is trisomy 13. Edward is trisomy 18.