Birth Defects RR

Question 1

Are Birth defects structural, functional, or behavioral disorders present at birth?

Answer 1

ALL

Question 2

What is the most common type of congenital defect?

Answer 2

Congenital Heart Defects

Question 3

What genes are implicated in Axenfeld-Reiger Syndrome?

Answer 3

PITX2 and FOXC1.

This is an example of a multisystem disease caused by mutations in a single or limited number of genes.

Question 4

What are modifier genes? How do they contribute to clinical variability?

Answer 4

Modifier genes are genes that in some way interact and affect the functionality of a disease gene (or any gene for that matter) While a disease may be attributed to a single gene, different people possess different modifier genes that compensate to different degrees and thus contribute to clinical variability. Environmental factors can also contribute.

Question 5

What is holoprosencephaly? What are some of the causes of this congenital anomaly

Answer 5

is a structural anomaly of the brain resulting from failed or incomplete forebrain division. This is an example of a single disease with multiple possible causes such as chromosomal abnormalities, mutations in a single gene(Shh signaling), or environmental factors, each of which are implicated on their own.

Question 6

What effects can hyperthermia in the mother cause on a developing embryo?

Answer 6

can interfere with neurulation and cause neural tube defects. ex viral infection causing a fever

Question 7

What is thalidomide? What birth defects does it cause?

Answer 7

A sedative similar to aspirin that was used widely in the 50s and 60s to treat morning sickness. Major defect was limb defects

Question 8

What is a teratogen?

Answer 8

an agent that causes birth defects

Question 9

What are some general categories of teratogens?

Answer 9

Drugs and Chemicals, Ionizing radiation, Hyperthermia, Infectious Microorganisms, Metabolic Conditions in the Mother

Question 10

What factors determine the susceptibility of a fetus to a given teratogen?

Answer 10

Genotype of the embryo (or mom). Developmental stage at the time of exposure. dose and duration of exposure

Question 11

What is the most sensitive period for birth defects?

Answer 11

3-8 weeks. (Most problems that occur in the first 2 weeks lead to spontaneous termination)

Question 12

What is Fetal Alcohol Spectrum Disorder?

Answer 12

It refers to all alcohol related defects. Fetal Alcohol Syndrome is the worst case of these.

Question 13

What are some clinical manifestations of Fetal Alcohol Syndrome?

Answer 13

Small head, flat midface, thin upper lip, small eye openings, low nasal bridge, smooth philtrum.

Question 14

What is the leading cause of congenital mental retardation?

Answer 14

Alcohol

Question 15

What are some proposed mechanisms for how alcohol interferes with embryo development?

Answer 15

cell migration and adhesion.
Cell proliferation and survival
Cell signaling and gene expression

Question 16

What correlation has been drawn between the use of SSRIs in pregnant mothers

Answer 16

Possibly leads to birth defects, specifically septal heart defects.

Question 17

What are some congenital heart defects associated with laterality defects?

Answer 17

Dextrocardia with atrial septal defects. Double outlet right ventricle. Transposition of the great arteries.

Question 18

What are some signs and symptoms of severe heart defects in newborns?

Answer 18

rapid breathing, cyanosis, fatigue, poor circulation

Question 19

What heart defects are associated with VCFS?

Answer 19

tetralogy of fallot and truncus arteriosus

Question 20

What is persistent truncus arteriosus?

Answer 20

No seperation between aorta and pulmonary trunk

Question 21

What is tetralogy of fallot?

Answer 21

Ventricular septal defects, pulmonary stenosis, overriding aorta, ventricular hypertrophy

Question 22

What portion of the heart do cardiac neural crest cells help form? What gene is involved in their migration?

Answer 22

The outflow tract. TBX1 gene