Genetic Disorders

Question 1

Mendelian Disorders

Answer 1

• mutation in a single gene with large effects, but strong selective forces maintain mutation in a population
• RARE, high penetrance
• i.e. sickle cell anemia

Question 2

chromosomal disorders

Answer 2

structural or numerical alterations in autosomes and sex chromosomes

• uncommon, high penetrance

Question 3

complex multigenic disorders

Answer 3

• more common, low penetrance
• environment and gene interactions (polymorphisms)
• i.e. atherosclerosis, DM, HTN, autoimmune disease

Question 4

mutation

Answer 4

permanenet change in the DNA

Question 5

germ cell mutation

Answer 5

gives rise to inherited disease

Question 6

somatic cell mutation

Answer 6

give rise to CA and congenital malformations

Question 7

missense mutation

Answer 7

• point mutation

- alter meaning of sequence of the encoded protein

Question 8

sickle cell mutation

Answer 8

missense mutation, glutatmic acid to valine in Beta-globin chain of hemoglobin

Question 9

nonsense mutation

Answer 9

• point mutation

- changed to stop codon

Question 10

frameshift mutation

Answer 10

deletion or insertion that is NOT a multiple of 3, alteration in a reading frame

Question 11

multiple of 3 deletion or insertion

Answer 11

reading frame intact- abnormal protein

Question 12

trinucleotide-repeat

Answer 12

amplification of a sequence of 3 nucleotides, almost all contain guanine and cytosine

Question 13

anticipation

Answer 13

a genetic disorder that is passed on to the next generation, the symptoms become apparent at an earlier stage with each generation. Most times, an increase in severity of Sx is also noted