Genetics

Question 1

Marfan syndrome: (AD)

• eye
• heart
• skeletal

Answer 1

• retinal detachment, lens dislocation
• aortic root dilation (risk of dissection)
• scoliosis, arachnodactily

Question 2

Pt with Marfan syndrome, what would you prescribe?

Answer 2

B blockers
ARBs
(To slow down aortic root dilation)

• also risk of spontaneous pneumothorax

Question 3

Ehlers Danos:

Skin, joint and wound healing manifestations?

Answer 3

Hyperextensive skin
Hyperflexible joints
Abnormal wound healing, wide atrophic scars
Autosominal dominat, type 5 collagen mutation

Question 4

4 year old child with multiple fractures, some have healed others have not
Normal height
Dx and additional findings

Answer 4

Dx osteogenesis imperfecta

Additional findings- brittle teeth (yellow sometimes), BLUE SCLERA

Question 5

Achondroplasia vs osteogenesis imperfecta genetics

Answer 5

Both AD,
Achondroplasia= type V collagen, OI= types 1- 4 collagen
Achondroplasia has short stature, OI has normal stature

Question 6

Noonan syndrome characteristic:

• facies
• heart defect
• skeletal defect

Answer 6

• facies: downslanting eyes, hooded eye lids, wide spaced eyes
• pulmonary valve stenosis —> HOCM later
• PECTUS DEFORMITY (anterior chest looks punched in)

Question 7

Noonan syndrome vs Turner’s syndrome

Answer 7

BOTH: wide spaced nipples, webbed neck
Edema of the feet!
Cardiac differences: 
- Turner’s syndrome: LEFT sided heart defects (coarctation, bicuspid aortic valve)
- Noonan: RIGHT sided heart defect (PVS)

Turners only girls

Question 8

VACTERL syndrome vs Fanconi anemia

Answer 8

Both: thumb/ radial hypoplasia!!
VACTERL (vertebral, anal, cardiac, TE, renal, limb)
Fanconi (congenital aplastic anemia- onset of aplastic anemia at age 7), BIRTH DEFECTS: renal tubular acidosis, SHORT STATURE, skin hypopigmentation!
Tx of fanconi- transfusions, bone marrow transplant, immunosuppression

Question 9

Baby with conotruncal heart defect, coloboma, genital hypoplasia, ear defective shape, choanal atresia?

Answer 9

CHARGE SYNDROME

Question 10

Cornelia De Lange- (memory: Frieda Fairy)

Answer 10

Frieda Kahlo: hirsuitism, unibrow
Fairy: upturned nose, long eyelashes, microcephaly
Upper limb deformities

Sporadic autosomal dominant

Question 11

Neurofibromatosis 1 characteristics

Answer 11

Cafe au lait spots
Cutaneous PLEXIFORM neurofibromas (look like myelin sheath etc)
Lisch nodules (iris hamartomas)
Incr risk for malignant gliomas and peripheral nerve sheath tumors

Question 12

Potter sequence

Answer 12

Oligohydramnios due to any reason
Lung hypoplasia
Limb positions abnormal
Potter facies compressed

Question 13

Mandibular hypoplasia likely other accompanying deformities:

Answer 13

Pierre Robin sequence:

• micrognathia
• posterior displacement of tongue
• cleft palate

Question 14

Child that is tall and thin and has developmental delay

Answer 14

Child has marfanoid habitus, so screen for HOMOCYSTINURIA,
Look for incr methionine / homocysteine in blood
Genetic testing
Remember MARFAN PEOPLE HAVE NORMAL DEVELOPMENT

Question 15

Homocystinuria vs Marfan syndrome

Answer 15

Both: tall, thin kids with possible lens dislocation
Homocysteinuria:
- inferior lens dislocation vs posterior dislocation(Marfan)
- increased risk of thromboembolism (vs aortic dilation Marfan)
*homocysteinuria= COGNITIVE DELAY, MARFAN= NORMAL INTELLIGENT

Drugs:
Homocysteine special diet, or betaine therapy (to lower HS in blood)
Marfan: b blocker or ARB

Question 16

1 day old BOY, present with Ammonia high >200, hyperventilation (causing respiratory alkalosis), Dx?

Answer 16

OTC deficiency, resulting in less ammonia converted to urea

Hyper ammonemia, hypotonia, HYPERVENTILATION

Question 17

OTC deficiency treatment

Answer 17

Low protein diet, with sodium benzoate to remove ammonia from body

Question 18

3 day old baby present with VOMITING, KETOTIC HYPOGLYCEMIA, hyperammonemia
Workup?

Answer 18

Check urine amino acids!!

MMA in urine or propionic acid (PA)

Question 19

Infant blond with blue eyes, hypotonia, musty odor of urine

Answer 19

Phenylketonuria

Tx restrict phenylalanine whole life

Question 20

Baby jaundice after breastfeeding, hypoglycemia, lethargy, cataracts after a while, PRESENT SIGNS OF SEPSIS, Dx?

Answer 20

Galactosemia baby with E COLI SEPSIS (metabolize galactose)

Question 21

3 month old baby, hypoglycemia, hyperlipidemia, hyperuricemia, HEPATOMEGALY:

Answer 21

Von Gierke disease (von GEEK disease)
Check glucose 6 phosphate levels
Careful- hepatic adenoma has malignant transformation potential

Question 22

Pompe disease sx

Answer 22

Pompe affects the PUMP - cardiomegaly

a glucosidase

Question 23

Child with ataxia, seizures and change of personality, mc Dx?

Answer 23

Wilson Disease! Look for kayser fleischer rings and low blood ceruloplasmin

Question 24

Obese child with hypotonia and short stature + hypogonadism Dx

Answer 24

Prader Willi! Remember, these kids become hyperphagic later in childhood

Question 25

Very friendly 6 year old girl, with intellectual disability, prominent forehead, wide mouth, Dx?

Answer 25

``` Williams syndrome (deletion on chromosome 7 —> ELASTIN) (Elfin facies!) Elastin = connective tissue Throat- hoarse voice Heart- aortic stenosis (supravalvular) ``` Other signs: long philtrum, upturned nose

Question 26

Angelman syndrome vs williams syndrome

Answer 26

A: silenced mum gene, W: deletion short arm chr 7 A: bouts of LAUGHTER, W: very friendly A: severe mental retardation, W: intellectual disability only A: microcephaly, W: NORMAL HEAD

Question 27

17 yo girl with delayed puberty, normal genitalia and primary amenorrhoea- mcc

Answer 27

High FSH and LH: - Turners Syndrome - ovarian failure before puberty Low FSH+ LH: - hypothalamic pituitary failure before puberty

Question 28

17 yo girl with amenorrhoea, normal puberty and normal genitalia

Answer 28

Low LH FSH: | - means too much sex hormone inhibiting hpaxis= complete androgen insensitivity syndrome

Question 29

MC cause of testicular pain in child aged >12 yo:

Answer 29

Testicular torsion Sx: acute pain in area, swollen testicles Dx: decreased uptake in technecium 99m (or decr flow in doppler) Tx: surgery immediately

Question 30

MC cause of testicular pain in boys <11 yo?

Answer 30

Testicular appendage torsion Sx: gradual/ acute pain, BLUE DOT seen through scrotum skin Dx: doppler normal/ incr flow Tx: pain meds