Video Transcript
The table provided shows some
different types of genetic tests used in genetic screening, with a brief description
of each. Huntington’s disease is a genetic
disorder that most commonly appears in a person around 35 to 40 years of age and
leads to the deterioration of cognitive function. A person whose father has just been
diagnosed with the disease wants to know their chances of developing it. Which type of testing would be most
appropriate to determine if this person is likely to also suffer from Huntington’s
disease? (A) Presymptomatic, (B) newborn,
(C) preimplantation, (D) carrier, (E) prenatal.
Our DNA is passed on to us from our
biological parents, including any genetic mutations they may have. Different genetic tests, as shown
in the table, can be used to screen for these mutations. Let’s add another row to this table
to show at what stage these tests can be performed in order to answer this
question.
Before conception, potential
parents can be screened to see if they carry mutations that can be inherited. For those who are performing in
vitro fertilization, or IVF, the embryos can be tested for genetic disorders 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 the fetus as a result of older couples conceiving. Newborn babies can also be screened
in order to catch any potential disorder early so it can be treated. Finally, adults can be screened for
genetic disorders. They might do this because they
have a family history and want to know what the chances of developing a disorder
might be.
This question refers to
Huntington’s disease, which occurs later in life and applies to this type of
testing. So the most appropriate type of
testing for this is given by answer choice (A), presymptomatic.
