Genetic Diseases And Their Mutations

Question 1

Huntington’s Disease

Mutation
Location
Pathogenesis

Answer 1

Mutation on HD gene on chromosome 4

CAG repeats on HTT on chromosome 4q16.3
-number repeats determines liklihood of getting disease

10-35: no risk
35-39: risk- may or may not exhibit symptoms
40+: will exhibit symptoms
*the more repeats, the earlier symptoms will set in
**symptoms and onset more severe if inherited from father

micro deposits ambyloid beta noted

Question 2

Neurofibromatosis 1 / Van Recklingsburg

Answer 2

Mutation on NF 1 gene on chromosome 17

Codes for neurofibromin

• tumor suppressor
• involved in RasGTPase cascade

Question 3

Familial AD

Answer 3

Ambyloid Precursor Protein
Presenillin 1 & 2

Improper cleavage on Ambyloid Precursor Protein forms Ambyloid Beta

Ambyloid Beta accumulates to form oligomers which form plaques and disrupt neuromonal communication

Question 4

Sporadic AD

Answer 4

APOE protein on chromosome 19

e4 allele, improper cleavage APP

Question 5

BRCA 1

Answer 5

Tumor suppressor gene on 17q21

• breast cancer in women
• prostate in men

Question 6

BRCA 2

Answer 6

Chromosome 13q21

*breast, pancreatic, laryngeal, melanoma, esophagus, colon, stomach and biliary

Question 7

Li-Fraumeni

Answer 7

Germline*mutation chromosome 17

Associated with E-cadherin gene, CHD1

Question 8

Cowden Syndrome

Answer 8

Mutation PTEN genes

Tumor suppressor

Question 9

Peutz-Jeghers

Answer 9

Mutation STK11 gene

Tumor suppressor

Question 10

FAP

Answer 10

APC mutation on Chromosome 5
-tumor suppressor

Can also have MYH mutation

Question 11

NPHCC

Answer 11

Defect in MLH 1, 2, 6 or PMS 2

-DNA mistmatch prepaid