Genetics

Question 1

Repeat seen in Huntington Disease

Answer 1

• CAG
• (C)audate has decreased (A)Ch and (G)ABA
• chromosome 4

Question 2

repeat seen in myotonic dystrophy

Answer 2

• CTG

- Cataracts, Toupee (early balding in men), Gonadal atrophy

Question 3

repeat seen in fragile X

Answer 3

• CGG

- Chin (protruding), Giant Gonads

Question 4

repeat seen in friedreich ataxia

Answer 4

• GAA
• Ataxic (GAA)it
• Chromosome 9

Question 5

Disorders associated with Chromosome 3

Answer 5

• VHL

- RCC

Question 6

Disorders associated with Chromosome 4

Answer 6

• ADPKD (PDK2)
• achondroplasia
• huntington Disease

Question 7

Disorders associated with Chromosome 5

Answer 7

• cri-du-chat (5p-)

- familial adenomatous polyposis (FAP)

Question 8

Disorders associated with Chromosome 6

Answer 8

• hemochromatosis (HFE)

Question 9

Disorders associated with Chromosome 7

Answer 9

• williams syndrome (congenital microdeletion of long arm. deleted region includes elastin gene)
• cystic fibrosis

Question 10

Disorders associated with Chromosome 9

Answer 10

Friedreich ataxia

Question 11

Disorders associated with Chromosome 11

Answer 11

• Wilms tumor

- β-globin gene defects (ie sickle cell disease, β-thalassemia, MEN1)

Question 12

Disorders associated with Chromosome 13

Answer 12

• Patau syndrome
• Wilson disease
• Retinoblastoma (RB1)
• BRCA2

Question 13

Disorders associated with Chromosome 15

Answer 13

• Prader-Willi syndrome
• angelman syndrome
• marfan syndrome

Question 14

Disorders associated with Chromosome 16

Answer 14

• ADPKD (PKD1)

- α-globin gene defects (ie α-thalassemia)

Question 15

Disorders associated with Chromosome 17

Answer 15

• neurofibromatosis Type 1
• BRCA1
• p53

Question 16

Disorders associated with Chromosome 18

Answer 16

Edwards Syndrome

Question 17

Disorders associated with Chromosome 21

Answer 17

Down Syndrome

Question 18

Disorders associated with Chromosome 22

Answer 18

• NF2

- diGeorge syndrome (22q11)

Question 19

Disorders associated with X Chromosome

Answer 19

• Fragile X
• X-linked agammaglobulinemia
• klinefelter syndrome (XXY)

Question 20

Robertsonian translocation commonly involves chromosome pairs:

Answer 20

Robertsonian translocation commonly involves chromosome pairs 13, 14, 15, 21 and 22

Question 21

Williams Syndrome

Answer 21

• congenital microdeletion of long arm of Ch 7
• deleted region includes elastin gene
• distinctive elfin face, intellectual disability, hypercalcemia (increased sensitivity to Vit D), wel-developed verbal skills, extreme friendliness with strangers, cardiovascular problems

Question 22

22q11 deletion syndromes

Answer 22

• microdeletion @ 22q11 –> variable presentation including: CATCH-22 due to abnormal development of 3rd adn 4th branchial pouches
• Cleft Palate
• Abnormal face
• Thymic aplasia –> T-cell deficiency
• Cardiac defects
• Hypocalcemia secondary to parathyroid aplasia
• includes DiGeorge and velocardiofacial syndromes

Question 23

DiGeorge vs Velocardiofacial syndrome

Answer 23

• DiGeorge: thymic, parathyroid and cardio defects

- Velocardiofacial syndrome: palate, facial and cardio defects