I dont have testing at 12 weeks, but i'm almost definetly sure they do not test for Tay Sachs.

Tay Sachs is a genetic disorder, which results in the death of the child, normally around 4 years i think.

It is predominetly found in the Ashkenazi Jewish community, and if you are considered high risk for Tay Sachs (i.e. Jewish), you are normally offered testing in high school or prior to marriage. I didn't have testing done, as DH was tested at school and is not a carrier, so it wouldn't matter if i was (autosomal recessive gene, so it needs both parents to be carriers for the offspring to be affected).

If you are not Jewish, or are Sephardi, then you chances of being a carrier are so remotely small, that basically you won't be tested unless there is something wrong with your child, and they feel a full genetic screening might be useful.

They tend to only do genetic testing if you are high risk because of 1) cost involved and 2) stress and upset involved in waiting for results etc.

Do you think you need testing for Tay Sachs? Is there a history in either you partners or your familys history? If yes, i suggest you contact a genetic councelling unit and your local hospital.

Hope that helps.