Blueprints Obstetrics Ch3

Front 1

AD risk of ds to offspring ?

Back 1

50%

Front 2

AR risk of ds to offspring if both parents carriers ?

Back 2

25%

Front 3

usu carried by mother & passed to sons

Back 3

XLR syndromes - ex. hemophilia
- sons have ds 50% of time
- daughters carriers 50% of time

Front 4

recurrent lung infections
irreversible lung damage
cor pulmonale

Back 4

CF (AR)

Front 5

what kills in CF ?

Back 5

lung ds & sequale

Front 6

pancreatic insufficiency
malabsorption
failure to thrive

Back 6

CF

Front 7

CF carrier rate in caucasians

Back 7

1 / 28

Front 8

chloride channel gene mutation

Back 8

CF

Front 9

sickle cell genetic defect

Back 9

point mutation in the gene for beta chain in hemoglobin
- causes HbS

Front 10

forms polymers when deoxygenated causing sickling

Back 10

HbS

Front 11

heterozygote advantage

Back 11

heterozygous sickle-cell carriers are malaria resistant
- inhospitable to P. vivax

Front 12

nl hemoglobin ?

Back 12

HbA

Front 13

founder effect

Back 13

Tay-Sachs (AR)
1 / 27 Ashkenazi Jews are carriers

Front 14

sx 3-10 months after birth
loss of alertness
hyperacusis (rxn to noise)
neuro degeneration
myoclonic / akinentic seizures
cherry red

Back 14

Tay Sachs
- death by age 4

Front 15

hexosamidase A deficiency

Back 15

Tay Sachs

Front 16

accumulation of gangliosides (GM2)

Back 16

Tay-Sachs

Front 17

Hereditary hemolytic anemias

Back 17

Thalessemias

Front 18

unpaired globin chains produce insoluble tetramers that precipitate in the cell and damage membranes
premature RBC destruction in splenic RES

Back 18

Thalessemias

Front 19

impairment of B-globin leading to xs alpha chains

Back 19

B-thalessemia

Front 20

Locations of the RES:

Back 20

bone marrow
liver
spleen

Front 21

Why are B-thalessemias usu dx after birth ?

Back 21

B-globin is only important when it would replace the alpha-globin as the major non-alpha chain.

Front 22

AR disorder
caused by any point mutation that decreases mRNA or protein

Back 22

B-thalessemia

Front 23

Coded for by 4 alleles

Back 23

alpha-thalessemia
2 of 4 mutations can occurs cis or trans
cis - asian, trans - black

Front 24

deletions of 1, 2, 3 or 4 genes causes an increasingly severe phenotype

Back 24

alpha-thalessemia

Front 25

pale, premature, hydropic infants
severely anemic, splenomegaly
no HbF, no HbA, 100% Hbalpha4

Back 25

Hb Bart

Front 26

deletion of 3 alpha globin chains

Back 26

HbH disease
- HBH is unstable B-tetramers which oxidize
- born w/ anemia, initial Hb is Hb Bart & some HbH
- w/in months becomes HbA, HbH

Front 27

alpha thalassemia trait

Back 27

two deletions

Front 28

milder phenotype
microcytic anemia
normal Hb electrophoresis

Back 28

alpha thalessemia trait

Front 29

one alpha chain deletion

Back 29

silent carriers

Front 30

both parents cis
both parents trans

Back 30

25% hydrops & fetal death
asymptomatic trans carrier

Front 31

Name two ways AR traits are introduced and maintained:

Back 31

founder effect (Tay-Sachs)
heterozygote advantage (sickle-cell ds)

Front 32

all cells in the body except RBCs contain these

Back 32

chromosomes

Front 33

extra or missing chromosomes

Back 33

aneuploidy

Front 34

trisomy & monosomy of any of the chromosomes exists, but usu results in:

Back 34

miscarriage

Front 35

choroid plexus cysts on US

Back 35

Edward's Syndrome (Trisomy 18)

Front 36

monosomy X
Klinefelter's syndrome

Back 36

Turner's syndrome 45, XO
47, XXY
- MC sex chromosome abnormalities

Front 37

cystic hygroma on US

Back 37

Turner's syndrome
- no screening test exists yet

Front 38

presence of 2 X chromosomes causes germ cells to die off when they enter meiosis

Back 38

Klinefelter's syndrome
- firm testes
- hyalinaization of the seminiferous tubules

Front 39

GI & respiratory

Back 39

endoderm

Front 40

CV, MM, genitourinary

Back 40

mesoderm

Front 41

nervous system, skin, sensory organs (hair, eyes, nose, ears)

Back 41

ectoderm

Front 42

days 22 - 23 (week 4)

Back 42

neural tube formation begins in the formation of the 4th and 6th somites

Front 43

NTDs

Back 43

MTHFR - encodes enzyme w/ reduced activity

Front 44

spina bifida

Back 44

lemon sign (concave frontal bones)
banana sign (cerebellum pulled caudally and flattened)

Front 45

increased AFP cx by ?

Back 45

open neural tube allows AFP into the maternal serum

Front 46

renal failure leading to anhydramnios
- pulmonary hypoplasia
- contractures in the fetus

Back 46

Potter's syndrome

Front 47

Potter's disease

Back 47

bilateral renal agenesis

Front 48

Epidemiology Sensitivity, PPV

Back 48

A / A + B, A / A + C

Front 49

LR+

Back 49

odds of an event after + test
prior * LR+ = posterior odds

Front 50

PAPP-A

Back 50

pregnancy associated plasma protein A

Front 51

Aneuploidy risk at 35:

Back 51

1 / 190

Front 52

choroid plexus cyst

Back 52

Trisomy 18

Front 53

echogenic intracardiac focus
LR+

Back 53

EIF Down Syndrome
1.5:2.0

Front 54

calcification of the papillary mm
- no particular pathophysiology

Back 54

EIF (5% of all pregnancies)

Front 55

3 ways to obtain fetal cells:

Back 55

amniocentesis
CVS
PUBS

Front 56

threshold for amniocentesis is same for risk for age. What is this risk ?

Back 56

1/200
Down v.
ROM, Preterm labor, fetal injury

Front 57

CVS cells are from the:

Back 57

placenta

Front 58

No need to culture before analysis b/c fetal cell count is so high.

Back 58

PUBS
- needle can then be used to trasfuse if necessary

Front 59

L1 US given at ?

Back 59

18-22 weeks

Front 60

recognizes hypoxic fetal brain injury sooner than US

Back 60

fetal MRI

Front 61

Fetal dx in 1st trim is by:
By second trim ?

Back 61

US
Amniocentesis

Front 62

Maternal DM SX:

Back 62

cardiac anomalies
macrosomia
post-partum bleeding