My Sister's double marker test comes positive with trisomy 21 increased 1:11 down syndrome. What to do next.What is the possibility od baby having down syndrome.our family has no history of such syndrome.

A. But these things are not based on the hereditary or if there is a family history these things can happen to anybody but as per the report it would be good if the gynaecologist give you a suggestion and clear your doubt about it because whatever that you have a Doctor Who specialised in these things can only give you a correct help on that