Genetics

Question 1

Mutation in ras/mitogen kinase signaling gene, seen in what disease?

Answer 1

Noonan

Question 2

Describe characteristics of infantile cortical hyperostosis (Caffey disease)

Answer 2

on physical exam there are hard swllings fixed to bone, movement of bone is limited

xrays show gradual cortical thickening, periosteal bone formation around diaphysis. most frequently affected locations are ascending ramus and angle of mandible

most cases sporadic
tibia is affected in familial cases

Question 3

Describe some features of Smith-Lemli-Opitz

Answer 3

associated with low unconjugated estriol
AR
microcephaly, hypospadias, heart murmur, wide-spaced eyes, and polydactyly of the left foot.
pyloric stenosis
renal dysgenesis

Question 4

Features of OTCD deficiency

Answer 4

elevated plasma alanine and glutamine levels
elevated urine orotic acid levels

plasma citrulline, arginine, and BUN levels decreased

Question 5

Physical Features of Smith-Lemli- Opitz?

Answer 5

micrognathia, flattened nose, cleft palate
hypotonia, pan systoli murmur, axial polydactly
renal agensis

defect in 7-Dehydrocholesterol reductase

Question 6

In what disorder do you see triphalangeal thumbs?

Answer 6

Diamond-Blackfan Syndrome

Question 7

In what disorders do you see cystic lymphangiomas?

Answer 7

Trisomy 13, 18, 21, and Noonan and Turner

Question 8

What is Hay-Wills Syndrome?

Answer 8

ectodermal, cleft lip palate syndrome
you see skin peeling, congenital strands of tissue around eyelids, lacrimal duct atresia, external ear malformation, hypospadiasis

Question 9

What is most pressing issue in neonatal period of those with achondroplasia?

Answer 9

evaluation of craniocervical junction, as many as 8% of infants may die due to compression of spinal cord due to cervical narrowing.

Question 10

What is Potter’s Face

Answer 10

Potter’s face refers to a parrot-beak nose, micrognathia, low-set ears, flattened nose, widely spread eyes, and the presence of skin folds from the edge of the eye

Question 11

What is triad of Pierre Robin Sequence

Answer 11

Micrognathia, posterior displacement of tongue, and upper airway obstruction

Question 12

What is Wardenberg Syndrome?

Answer 12

a rare genetic disorder characterized by deafness, pigmentation anomalies (hair and eyes), and minor deficits in anatomical structures that evolve from the neural crest.
It is now known that selective disruption during myogenesis, especially in the mutation of gene PAX3, is the cause of Waardenburg syndrome

Question 13

What would prenatal imaging show for Turner’s Syndrome?

Answer 13

ultrasound reveals cystic hygroma, increased nuchal translucency, coarctation of the aorta/left-sided cardiac anomalies, brachycephaly, horseshoe kidney, polyhydramnios, oligohydramnios, or non-immune fetal hydrops.

Question 14

3 different ways BWS inherited

Answer 14

loss of methylation maternal chromosome 11 (50%)
parental disomy (20%)
gain of methylation (5%)

Question 15

VACTERL association

Answer 15

Vertebral Anomalies
Anal Atresia
Cardiac (VSD > TOF > Coarc)
TE fistula
Renal anomaly
Limb dysplasia

Question 16

Clinical features Townes Brock Syndrome

Answer 16

imperforate anus, dysplastic ears, thumb anomalies

Question 17

In what different genetic conditions do you see mutations in FGF 2?

Answer 17

Apert and Crouzon syndrome

Question 18

Differences between Apert and Crouzon

Answer 18

Apert greater risk of mental deficiency
Apert midface hypoplasia, crouzon maxillary hypoplasia

Apert irregular craniosynostosis
Crouzon, premature craniosynostosis

Crouzon, curved beaked nose
Apert syndactyl and broad distal phalynx, thumbs and toes
Apert Cardiac defects

Question 19

List some features of Sturge-Weber Syndrome?

Answer 19

Port wine stain
tramline intracortical calcifications
glaucoma
seizures
macrocephaly
cardiac rhadbomyomas

Question 20

DNA Testing mnemonic
SNW DRP

Answer 20

Question 21

Trisomies result from an extra copy of which parent?

Answer 21

mother

Question 22

Holt Oram syndrome

Answer 22

AD
Cardiac defects (ASD)
upper limb defects
absent or hypoplastic thumbs
hypertleroism

Question 23

Angeleman

Answer 23

microdeletion from mother
wide spaced mouth, large teeth
puppet like gait, neuro abnormalities

Question 24

Prader Wili

Answer 24

deletion from paternal origin
small hands feet
almond shaped eyes
hypogenitalia
obesity

Question 25

Rubenstein-Taybi

Answer 25

cardiac defects, broad thumbs, toes,
hypoplastic maxilla
hirsutism
downward slanint palpebral fissures

Question 26

X-linked recessive. Classic findings include brittle, light-colored (white/gray) hair, thin/absent eyebrows, hyperelastic skin, full cheeks, and a high-arched palate

Answer 26

Menkes disease
(x linked recessive)
copper transport issue

Question 27

What is incidence of minor congenital anomalies vs major congenital anomalies.

Answer 27

20% minor
3% major

Question 28

What is a cis-acting regulatory element?

Answer 28

regions of non-coding DNA that regulate gene transcription
promoters, enhancers, repressors are examples

Question 29

High forehead, large fontanelles, hypertelorism, and micrognathia.
with increased plasma VLFCAs and absent peroxisomes within the cells.

Answer 29

Zewellger Syndrome