Ob-Gyn questions? Ask a gynecologist online.
How old is your wife? That factors in to the answer. An isolated echo genie cardiac focus is never a reason for amino. In higher risk pregnancies, over 35 or abnormal screening, an amino should be offered. 3-5 percent of normal fetuses have this finding. Up to 30 percent in Asians. It increases the risk of trisomy 21 2-5 times over the calculated risk. Still very low. But yes it's not 1/100000. Nor is it high enough at all to warrant amino.
The miscarriages with "genetic defects" place her in a high risk group. What were the diagnosis? You should obtain a consult with a maternal fetal medicine specialist to discuss further testing.