Chromosomal instabilities

Question 1

[Gen/Chr insta/CdLS]

Facial characteristics of Cornelia de Lange syndrome? (4)

Answer 1

1. Downturned mouth, thin upper lip
2. Micrognathia
3. Low hairline
4. Synophrys (eyebrow fusion), long eyelashes

Question 2

[Gen/Chr insta/CdLS]

Body characteristics of Cornelia de Lange syndrome? (4)

Answer 2

1. Microbrachycephaly (small, flat head)
2. Micromelia (small hands/feet),
3. Phocomelia (hands/feet closely attached to the body)
4. 2/3 Syndactyly of toes

Question 3

[Gen/Chr insta/CdLS]

Developmental/Neurological symptoms of Cornelia de Lange syndrome? (4)

Answer 3

1. Intrauterine growth restriction, poor growth
2. Microcephaly
3. Intellectual disability, autism, behavioral issues
4. Hearing loss

Question 4

[Gen/Chr insta/CdLS]

Anomalies other than neurologic of Cornelia de Lange syndrome? (4)

Answer 4

1. Eye: Myopia
2. GI: GI reflux
3. Heart: Cardiac defects
4. GU: Renal anomalies, genital anomalies

Question 5

[Gen/Chr insta/AT]

Causal gene for ataxia-talengiectasia?

Answer 5

ATM gene
(Autosomal recessive)

Question 6

[Gen/Chr insta/AT]

Classic ataxia-talengiectasia neurologic features? (3)

Answer 6

1. progressive cerebellar ataxia (ages 1-4 years)
2. oculomotor apraxia
3. choreoathetosis

Question 7

[Gen/Chr insta/AT]

Classic ataxia-talengiectasia other than neurologic features? (3)

Answer 7

1. Telangiectasias of the conjunctivae
2. Immunodeficiency, frequent infections (sinopulmonary, bronchiectasis)
3. An increased risk for malignancy, particularly leukemia and lymphoma

Question 8

[Gen/Chr insta]

Name of syndrome?

With ataxia, frequent infection, malignancies

Answer 8

Ataxia telangiectasia

Question 9

[Gen/Chr insta/FA]

Physical features of Fanconi anemia? (5)

Answer 9

1. Cafe au lait, hypopigmentation
2. Hypoplastic thumb and radius
3. microcephaly, short stature
4. ophthalmic anomalies
5. genitourinary tract anomalies

Question 10

[Gen/Chr insta/XP]

Characteristics of Xeroderma pigmentosum? (3)

Answer 10

1. Acute sun sensitivity: severe sunburn with blistering, persistent erythema on minimal sun exposure with marked freckle-like pigmentation of the face before age two years
2. Sunlight-induced ocular involvement: photophobia, severe keratitis, atrophy of the skin of the lids, ocular surface neoplasms
3. Greatly increased risk of sunlight-induced cutaneous neoplasms

Question 11

[Gen/Chr insta/Bloom]

Clinical features of Bloom syndrome? (5)

Answer 11

1. Pre- and postnatal growth deficiency
2. Immune abnormalities
3. Sensitivity to sunlight
4. Insulin resistance
5. High risk for cancers
   (normal intellectual ability)