Question

A pregnant woman has come to you for counseling. She is in her late forties and this is her first pregnancy. She has had a difficult pregnancy and is very worried about having a miscarriage. She has come to you to determine whether her child will be born with Down Syndrome.

a. Explain what test or tests you would suggest that could answer her question.

b. Explain to her why you would recommend this test.

c. What results would you expect if the fetus does indeed have Down syndrome?

Answer 1

a. Chorionic villus sampling (Cells collected from the placenta) or amniocentesis (Cells collected from amniotic fluid) are the two tests to be carried out to check the chromosomal make up of the foetus. Once the sample is collected, the chromosomal count will be checked by karyotyping.

b. She is in her late forties. Having first child at this age is highly risk for developing syndromes. Aged germ cells will cuase these kinds of issues. So, it is always recommended to people who carry children in their later stage of reproduction.

c. Down syndrome has the chromosomal make up of 21 trisomy. There is an extra copy in the 21st chromosome. If the child is positive for this syndrome, there will be an extra chromosome 21 in all her cells.