Patient's question:
Down syndromeDoctor's answer:
The recurrence risk rate for standard trisomy 21 is 1%, and the risk increases with the mother's age. For translocation-type patients, both parents should undergo karyotype analysis to identify balanced translocation carriers: if the mother has a D/G translocation, the risk for each pregnancy is 10%; if the father has a D/G translocation, the risk is 4%. Most G/G translocation cases are sporadic, with parents typically having normal karyotypes. However, 21/21 translocation carriers have been identified, and their offspring have a 100% risk of developing the condition.