genetics

Question 1

down syndrome - fetal markers

Answer 1

low AFP, low estriol, high betaHcG

Question 2

trisomy 18 - fetal markers

Answer 2

low AFP, low estriol, low betaHCG

Question 3

marfan syndrome

Answer 3

auto dom, chromo 15 for fibrillin
Sx: tall stature, elongated extremities, long fingers
- upward lens subluxation/retinal detachment
- aortic root dilatation

Question 4

prader willi syndrome

Answer 4

genomic imprinting of paternal 15
Sx: almond shaped eyes, fishlike mouth
- FTT obesity from hyperphagia, short stature
- hypotonia, MR, hypogonadism

Question 5

angelman syndrome

Answer 5

happy puppetm genomic imprinting of maternal 15
Sx: jerky arm movements, ataxia, inappropriate laughter, MR
- microcephaly, tongue protrusion

Question 6

noonan syndrome

Answer 6

chromo 12
Sx: short stature, shield chest
- short webbed neck and low hairline, right sided heart lesions (pulmonary valve stenosis) –> vs turner’s syndrome with left sided heart lesions
- MR

Question 7

digeorge syndrome

Answer 7

deletion at chromo 22q11

CATCH-22
- cardiac, abnl facies, thymic hypoplasia, cleft palate, hypocalcemia

Sx: short palpebral fissures, small chin, ear abnl

• aortic arch anomalies, tetralogy of fallot
• thymus and parathyroid hypoplasia - cell mediated immunodeficiency, severe hypocalcemia

Question 8

velocardiofacial syndromes

Answer 8

deletion at chromo 22q11

CATCH-22
- cardiac, abnl facies, thymic hypoplasia, cleft palate, hypocalcemia

Sx: cleft palate, wide nose, fish mouth

• VSD and right sided aortic arch
• neonatal hypotonia, MR

Question 9

ehlers danlos

Answer 9

defective type V collagen
Sx: hyperextensible joints
- loose fragile skin, tissue paper-thin scars
- mitral valve prolapse, aortic root dilatation and fragile blood vessels
- constipation, rectal prolapse

Question 10

osteogenesis imperfecta

Answer 10

abnl type 1 collagen
Sx: blue sclerae
- fragile bones, joint laxity, osteoporosis, osteopenia
- yellow or gray-blue teeth
- easy bruising
- conductive hearing loss, skeletal deformities`

Question 11

williams syndrome

Answer 11

cocktail party personality, deleton on chromo 7

Sx: elfin facies, MR/loquacious personality, aortic stenosis, hypercalcemia, hoarse voice/hernias

Question 12

cornelia de lange syndrome

Answer 12

Sx: small of gestational age and FTT

• single eyebrow, microcephaly, thin lip
• infantile hypertonia
• MR
• small hands and feet, cardiac defects
• self destructive

Question 13

russell silver

Answer 13

Sx: small for gestational age

• small triangular face, down turned mouth
• short stature and limb asymmetry
• cafe au lait spots on skin
• excessive sweating

Question 14

pierre robin syndrome

Answer 14

micrognathia, cleft lip and palate, large tongue

Question 15

cri du chat

Answer 15

deletion of 5

Sx: slow growth, microcephaly, MR

Question 16

Down syndrome

Answer 16

epicanthal skin folds, upslanting palpebral fissures, brushfield spots
- hypotonia
- MR
- single palmar creases
- duodenal atresia
- endocardial cushion defects (40%)
- cervical spine instability (20%)
- leukemia
hypothyroid
- cataracts, glaucoma

Question 17

Trisomy 18

Answer 17

more common in females
Sx: MR, hypertonia, delicate small facial features
- rocker bottom feet, clenched hands

Question 18

Trisomy 13

Answer 18

midline defects

Sx: holoprosencephaly, MR, microphthalmia, retinal dysplasia, cleft lip/palate

Question 19

galactosemia

Answer 19

hypoglycemia and HSM in infants

Question 20

fragile x

Answer 20

large ears, large testes, MR