Genetics Abnormal Amnio Teratology

Front 1

what is the difference between a teratogen and a mutagen?

Back 1

mutagen - agent that causes mutations in a gene in either mother or father

teratogen - really must affect the mother, ie if father drinks alcohol this will not cause fetal alcohol syndrome

Front 2

What is thalidomide?

Back 2

treats leprosy

if taken between 21-35 days
after implantation causes limb reduction (symmetrical) heart defects cleft lip ear malformations and duodenal atresia

Front 3

FDA rating of teratogenicity
class A
B
C
D
X

Back 3

A - no risk
B - no human risk
c - unknown human risk
D - evidence of human risk
E - fetal risk outweighs any benefit to mother

Front 4

phenocopy

Back 4

looks like genetic abnormality but really was environmental

ie) Holt-Oram syndrome, maternal diabetes embryopathy, VATER association)

* V = Vertebral anomalies; and
* A = Anal atresia (no hole at the bottom end of the intestine);
* C = Cardiac defect, most often ventricular septal defect;
* TE = TracheoEsophageal fistula (communication between the esophagus and trachea) with esophageal atresia (part of the esophagus is not hollow);
* R = Renal (kidney) abnormalities; and
* L = Limb abnormalities, most often radial dysplasia (abnormal formation of the thumb or the radius bone in the forearm).

Front 5

Maternal infections

Back 5

TORCH
Taxoplasmosis - cat feces
Rubella -

Cytomegalovirus -
Herpes - transplacental transmission (usually in birth canal exposure)usually go for cesarean


others - varicella, parvovirus, syphilis pg 369

Front 6

exposure to a teratogen in the first trimester will most likely cause? what about in late pregnancy?

Back 6

first trimester - probably CNS , later hearing impairements and cataracts

Front 7

Drug ingestations or environmental exposure:
Radiation

Back 7

prior to 8 weeks all or none rule results in miscarriage, 8-15 weeks there is a dose response , later exposure has an increased risk for leukemia (timing is important)

radiation can cause cytoenetic breakage

Front 8

drug ingestations:
Alcohol

Back 8

first trimester exposure - more than 2oz a day = fetal alcohol syndrome, small head, delay in development and facial appearance

Front 9

drug ingestation:
Anticonvulsants
ex)
and symptoms for each,
what do you do to reduce risk?

Back 9

ie dilantin
cleft lip small size fingernail hypoplasia, developmental delay

valproic acid -neural tube defects if exposure n first trimester

reduce risk - folic acid summplements 2-3 mo before pregnancy

Front 10

Maternal Diabetes

Back 10

type I - insulin dependent
fetuses have hyperglycemia in first trimester, results in malformations

Gestational diabetes - glucose levels in third trimester cause macrosomia(lrg size)

Front 11

Maternal systemic lupus and Phenylketonuria

Back 11

lupus -increased miscarriage risk

PKU - dose relationship with microcephaly and congenital heart disease

Front 12

Bendectin

Back 12

so many suits it was taken off the market, but never formally proved to be a teratogen,

Front 13

timing
preconception
preimplantation
predifferenctiation
organogenesis
postorganogenesis
birth and after

Back 13

preconception - none
pre-implant - some protection
predifferentiation - "all or nothing effect"
organogenesis - most affected here
postorganogenesis - some agents can cause effects thruout preg
birth - not teragotenic effect

Front 14

What would the dose response curve be affected by?

Back 14

metabolite clearance
metabolites
enzymes for degradation
alcohol and cigarettes

Front 15

Genetic susceptibility depends on?

Back 15

fetal modifier genes, how conceptus interacts with environmental factors,
maternal rate of absoprtion, animal studies reduce human risk

Front 16

congenital malformation, isolation vs several

Back 16

isolation - look for other malformations

pattern of anomolies - could be a synd/assoc, numbers might change

Front 17

malformation

Back 17

start off intrinsically abnormal

Front 18

disruption

Back 18

destructive, process starts off normally and then destroyed
ie amniotic band sequence
TERATOLOGY, structure of tissue was normal, intro of teratogen
blood clot causing disruption of normal development

Front 19

deformation

Back 19

things were working well and prevented it from developing normally, structure still there, just different, ie oligohydramnios, uterus presses on foot and foot grows abnormally

Front 20

dysplasia

Back 20

started off abnormally in terms of single tissue and the tissue develops abnormally

achondroplasia - abnormal bone growth

Front 21

sequence

Back 21

etiolog (urethral obstruction, etc ) --> oligohydramnios --> phenotype (pulmonary hypoplasia, failed lung development)

seq. - pathogenic feature that leads to a phenotype, BUT the etiology can be diff, is can be from urethral obstruction or chronic leakage or polycystic kidney disease, all these lead to the sequence of oligohydramnios

Front 22

developmental fields

Back 22

a developmental field would be ex) pharyngeal pouch (becomes parathyroid, facial structures, etc)

george syndrome

Front 23

syndrome

Back 23

know underlying problem and see patterns

Front 24

genetic counseling, know when to do it and underlying ideas

Back 24

lkh