Down Syndrome Can Be Caused by Either Trisomy 21 or a Robertsonian

Question

Down syndrome can be caused by either trisomy 21 or a Robertsonian translocation.

Accepted Answer

Trisomy 21 and Robertsonian translocation are both known causes of Down syndrome. Trisomy 21 is the most common cause, accounting for about 95% of cases, while Robertsonian translocation accounts for about 4% of cases.