Genetics & Metabolic

Question 0

Fetal hydantoin syndrome

Answer 0

Phenytoin exposure -> craniofacial abnormalities, hypoplastic phalanges/nails

Question 1

VACTERL

Answer 1

Vertebral
Anal atresia
Cardiac (PDA, asd, vsd)
TracheoEsophageal fistula
Renal
Limb anomalies

Question 2

Ashkenazi Jews common carriers of gene mutations causing these syndromes

Answer 2

Tay-Sachs (CNS no visceral), Niemann Pick (CNS and HSM) and Gaucher type 1 (no CNS)

Question 3

hypoketotic hypoglycemia, hypotonia, cardiomyopathy, SIDS

Answer 3

fatty acid oxidation defects

Question 4

1-2% of patients with PKU actually have defect of this carrier protein

Answer 4

tetrahydrobiopterin

Question 5

maternal PKU teratogenic effects

Answer 5

growth deficiency, microcephaly, mental retardation, congenital heart defects

Question 6

branched chain amino acids elevated in maple syrup urine disease

Answer 6

valine, leucine, isoleucine, alloisoleucine

Question 7

associated with macrocephaly, subdural hematomas, and retinal hemorrhages

Answer 7

glutaric aciduria

Question 8

associated with black urine, deposits in ears, sclera and joints

Answer 8

alkaptonuria, defect in tyrosine metabolism

Question 9

urea cycle defect that is inherited as xlinked

Answer 9

OTC deficiency

Question 10

which lysosomal storage disease is x-linked

Answer 10

Fabry disease

Question 11

which mucopolysaccharidosis is xlinked

Answer 11

Hunter, no corneal clouding

Question 12

Name the disorders passed down by XL dominant:

Answer 12

Rett syndrome 
Vitamin D resistant rickets
Fragile X
Charcot Marie tooth
Most alports

Question 13

What test should be recommended on a baby with achondroplasia?

Answer 13

Polysomnography because risk of central apnea from arterial compression at foramen magnum.
CT or MRI of brain and upper spinal cord for same reason.
most common cause of sudden death is cervicomedully jxn compression

Question 14

What screening labs indicate increased risk of Down’s syndrome?

Answer 14

LOW AFP, estradiol

HIGH hcg, inhibin

Question 15

CHARGE

Answer 15

Coloboma
Heart defects
Atresia choanae
Retardation of growth and development
GU anomalies (cryptochordism)
Ear abnormalities and deafness

Question 16

CF carrier risks

Answer 16

patient with siblings who have CF (carrier risk 2/3)

general carrier risk in white population is 1/29

Question 18

timing of development of features of NF1

Answer 18

first café au laits –> axillary freckling (3-5 yrs) –> neurofibromas (onset of puberty), then lisch nodules and hamartomas (early adulthood)

Question 19

timing of development of skin findings of tuberous sclerosis

Answer 19

Ash leaf spots (birth) hypopigmented macules –> facial angiofibromas (2-6 yrs) –> shagreen patch (cobblestone orange peel) –>periungal fibromas (puberty)

Question 20

what nevi has greatest risk of melanoma

Answer 20

giant congenital nevi