Video Transcript
The table provided shows some
different types of genetic tests used in genetic screening, with a brief description
of each. Tay-Sachs disease is a genetic
disorder that destroys nerve cells in the brain and, in young children, is
fatal. A couple that both have a history
of Tay-Sachs disease in their families are hoping to conceive a child but are
concerned that they could pass on the disorder. What type of genetic test would be
most appropriate for this couple? (A) Presymptomatic, (B)
preimplantation, (C) carrier, (D) newborn, (E) prenatal.
Our DNA is passed on to us from our
biological parents, including any genetic mutations they may have. Different genetic tests can be used
to screen for these mutations in order to minimize the inheritance of disease. This table indicates different
genetic tests that can be performed at different stages. Let’s add a new row and identify
the stages that these tests are performed.
Before conception, potential
parents can be screened to see if they carry mutations that can be inherited. For those who are using in vitro
fertilization, or IVF, they can test the embryos to see if they’ve inherited a
genetic disorder before using them for a pregnancy. While the fetus is developing,
disorders that are not inherited can be screened for, for example Down syndrome. This type of disorder can occur
more frequently in older women.
Newborn babies can be screened in
order to catch any potential disorders early on so they can be treated
appropriately. Finally, adults can be tested when
there’s a family history of a disease that occurs later in life. This can help them prepare for it
by seeking early treatments, for example.
In this question, a couple is
planning on having a child, but they both have a history of Tay-Sachs disease in
their families. The genetic test that is most
appropriate to screen these potential parents before conception is given by answer
choice (C) carrier.
