Medical Genetics Final Exam Review.
Question and answers. Newest!!!!!
Dysmorphology - the study of congenital birth defects that alter the shape/form of the
body of the newborn
Pleiotropy - single agent (gene or teratogen) results in abnormalities of many organs,
structures, etc....
Syndrome - causative agent causes multiple abnormalities in parallel
Sequence - agent affects only a single organ system at one point in time and that
defect results in secondary effects
What does your textbook say that the genome inaccurately described as a "master
blueprint"? - It does not specify how the materials are to be used, assembled, and their
final dimensions.
The genome specifies a set of interacting proteins and noncoding RNA's that set in
motion growth, migration, differentiation, and apoptosis.
These processes result in correct structures with a high degree of probability.
What are the two types of invasive testing? At what gestational age can these be
performed? - Amniocentesis - about 15-16 weeks fetal chromosome analysis
Chorionic Villus Sampling - about 10-12 weeks
What does noninvasive testing include? - Screening of the maternal serum and
ultrasound
The best information comes from a combination of these.
What is alpha-fetoprotein? How can this be tested in the maternal serum? - Alpha-
fetoprotein is a glycoprotein excreted by the fetus and enters the maternal blood stream
by placenta and amniotic membranes.
This can be immunoassayed by amniotic fluid AFP or maternal serum AFP.
Elevated levels indicate NTD (neural tube defect) and ultrasounds are done to raise
accuracy of MSAFP.
What is nuchal translucency? - Nuchal translucency is the thickness of the echo-free
space between the skin and soft tissue overlying the dorsal aspect of the cervical spine.
This is increased during the first trimester and must be determined with reference to
gestational age.
Increased NT is a sign of down syndrome.
Why can these tests alone not give accurate information? Discuss Figure 15-3, false-
positives, false-negatives. (Table 15-6) - MSAFP has too much overlap for unaffected
Question and answers. Newest!!!!!
Dysmorphology - the study of congenital birth defects that alter the shape/form of the
body of the newborn
Pleiotropy - single agent (gene or teratogen) results in abnormalities of many organs,
structures, etc....
Syndrome - causative agent causes multiple abnormalities in parallel
Sequence - agent affects only a single organ system at one point in time and that
defect results in secondary effects
What does your textbook say that the genome inaccurately described as a "master
blueprint"? - It does not specify how the materials are to be used, assembled, and their
final dimensions.
The genome specifies a set of interacting proteins and noncoding RNA's that set in
motion growth, migration, differentiation, and apoptosis.
These processes result in correct structures with a high degree of probability.
What are the two types of invasive testing? At what gestational age can these be
performed? - Amniocentesis - about 15-16 weeks fetal chromosome analysis
Chorionic Villus Sampling - about 10-12 weeks
What does noninvasive testing include? - Screening of the maternal serum and
ultrasound
The best information comes from a combination of these.
What is alpha-fetoprotein? How can this be tested in the maternal serum? - Alpha-
fetoprotein is a glycoprotein excreted by the fetus and enters the maternal blood stream
by placenta and amniotic membranes.
This can be immunoassayed by amniotic fluid AFP or maternal serum AFP.
Elevated levels indicate NTD (neural tube defect) and ultrasounds are done to raise
accuracy of MSAFP.
What is nuchal translucency? - Nuchal translucency is the thickness of the echo-free
space between the skin and soft tissue overlying the dorsal aspect of the cervical spine.
This is increased during the first trimester and must be determined with reference to
gestational age.
Increased NT is a sign of down syndrome.
Why can these tests alone not give accurate information? Discuss Figure 15-3, false-
positives, false-negatives. (Table 15-6) - MSAFP has too much overlap for unaffected
