Peds - Genetic Evaluations

Question 1

What is the cause of Down Syndrome?

Answer 1

Presence of a 3rd #21 chromosome (Trisomy 21)

Question 2

What increases risk for having a child with Down Syndrome?

Answer 2

Increased maternal/paternal age

Question 3

What are the medical comorbidities associated with Trisomy 21?

Answer 3

• Seizures
• Congenital heart disease
• Endocrine disturbances (DM & Thyroid)
• Esophageal/duodenal atresia (swallowing / GI disorders)
• Hearing / vision impairment
• Obesity
• Leukemia (4x greater risk)
• Early dementia

Question 4

What phenotypic findings would you expect to see on exam in someone with Trisomy 21?

Answer 4

• Brushfield spots** (star inside iris w/spot at each end)
• Inner epicanthal folds
• Microcephaly
• Upward slanting eyes
• Flattened nose
• Protruding tongue
• Single palmar crease
• Hypotonia
• Delayed growth & development

Question 5

What is the other name for XXY syndrome?

Answer 5

Klinefelter’s

Question 6

In which sex do you typically see Klinefelter’s?

Answer 6

Only found in males.

Question 7

When would you expect to see physical manifestations of XXY syndrome?

Answer 7

Typically presents at puberty. Infant will appear normal. May present initially as infertility.

Question 8

What are the typical phenotypical manifestations of Klinefelter’s syndrome?

Answer 8

• Tall stature
• Gynecomastia
• Underdeveloped secondary sexual characteristics
• Abnormal body proportions
• Transverse crease
• Learning disabilities
• Personality impairment

Question 9

XO Karyotype is also known as ________________.

Answer 9

Turner’s Syndrome

Question 10

In which sex do you typically see Turner’s Syndrome?

Answer 10

Females, 95% of embryos don’t survive to term

Question 11

What are the typical phenotypical manifestations of Turner’s syndrome?

Answer 11

• Webbed neck
• Low hairline
• “Shield” shaped chest
• Hypertension
• Bicuspid aortic valve, coarctation of aorta
• Lack of secondary sex characteristics
• Head / neck anomalies
• Lymphedema
• Learning disabilities

Question 12

You have a young athlete presenting for a sports physical who has a very tall, with arm span exceeding height, thin extremities and fingers, and pectus excavatum. What genetic disorder do you suspect? What would you want to pay special attention to during physical exam?

Answer 12

1) Marfan’s Syndrome - (can also have pectus carinatum)
2) Special focus on cardiovascular (listen for murmur).
- Aortic regurgitation
- Mitral valve prolapse
- Aortic aneurysm

Question 13

What is Marfan’s syndrome?

Answer 13

An inherited connective tissue disorder affecting skeletal, cardiac, and opthalmic body systems.

Question 14

You have an Ashkenazic Jewish women presenting to your clinic for OB genetic screening, what genetic disorder are you specifically screening for?

Answer 14

Tay-Sachs

Question 15

When do they symptoms of Tay-Sachs first appear?

Answer 15

Between 3 - 6 months of age.

Question 16

What is the typical progression of Tay-Sachs?

Answer 16

• Decreased muscle tone (1st symptom)
• Cherry red macula (diagnostic of Tay-Sachs)
• Listlessness
• Blindness
• Deafness
• Seizures
• Dementia
• Vegetative state
• Death

Question 17

You notice the following anomalies, 
- lateral displacement of the inner canthi
- short palpebral fissures
- short philtrum
- micrognathia 
- ear anomalies
What syndrome do you anticipate?

Answer 17

DiGeorge (Velocardiofacial) Syndrome

Question 18

Which genetic syndromes have cardiovascular involvement?

Answer 18

1) Turner’s Syndrome
2) Marfan’s Syndrome
3) DiGeorge