Week 5 embryo -- Teratogens and birth defects

This one also includes review from previous in class exams due to the content being a bit shorter

Human birth defects account for what % of infant deaths in North America?

20%

T/F 50-60% of birth defects have unknown etiology

true

What percent of birth defects result from disruptive actions of drugs/viruses/environmental factors

7-10%

T/F congenital rubella defects arise when mom has a chronic infection

False, mom must have an acute infection

What is the classic triad of congenital rubella?

PDA, Cataracts, deafness, ± a “blueberry muffin rash”

Cataracts, microcephally, hearing loss, and cardiac defects could be caused by what teratogen?

Rubella

Fetal anomalies from high maternal blood sugar levels

Microcephaly, cardiac, neural tube, caudal regression, limb reduction 

Fetal anomalies from maternal thalidomide exposure

limb reduction

Fetal anomalies from primary zika infection

microcephaly

Fetal anomalies from carbamazepine/seizure medication

Neural tube defects

Disruption defects start out as ___ and become ____

normal, abnormal

Deformation defects start out as ___ and becomes ____ from ____

normal, abnormal, mechanical forces 

Dysplasia defects are ____

abnormal organization of cells in tissues and its morphologic results

T/F Malformation defects start out as normal, but then spontaneously become abnormal

False, they start out as abnormal, and are often complex in nature

Name the defects in polytopic field defects

Cardiac defects, anal atresia, limb abnormalities, vertebral defects, renal anomalies, tracheo-esophageal fistula

What is a sequence vs a syndrome

Both are pattern of multiple defects. Sequences are formed form a single known or presumed structural defect/mechanical factor, and syndromes are thought to be pathogenically related but not known to represent a single sequence or polytopic field defect.

What is the name for statistically related defects that are not related pathogenetically or causally 

Association

T/F most early embryos with chromosome abnormalities can survive to blastulation 

False, most never undergo normal cleavage 

What is the occurence rate of turner syndrome

1:8000

This is the most common cytogenetic abnormality that causes SAB,

monosomy X /turner syndrome

Which parent (maternal or paternal) usually causes monosomy X?

paternal X is missing, 75% of the time

This syndrome is 50% of chromosomally abnormal pregnancies

T21

A neonate presents with VSD, rocker bottom feet, and flexed digits at birth. What chromosomal abnormality might they have?

Trisomy 18/Edwards syndrome

An ultrasound shows that a fetus has cleft lip, polydactyly, and CNS malformations. What trisomy might they have?

T13/Patau’s syndrome