Early in Their Marriage, in Their Mid-20s, Charles and Leona

Essay

Early in their marriage, in their mid-20s, Charles and Leona had two normal children, a boy and girl.Later, when Charles and Leona were both 42 years old, Leona unexpectedly became pregnant again in spite of the birth control methods the couple had practised for many years.Both parents were in good physical health and there was no history of genetic disorders in either of their families.Still, they wondered about the risks of a genetic or chromosomal disorder in their child-to-be.(a) What might a genetic counsellor tell the parents about their chances of having a Down syndrome child? (b) What methods might be employed to determine if the fetus is normal prior to birth? (c) What other kinds of defects might these methods detect?