8/15 - Genetic Disorders

Question 1

human genetic disorders are broadly classified into what categories

Answer 1

1. mutations in SINGLE genes w/ large effect disorders
2. chromosomal disorders
3. complex multigenic disorders

Question 2

what mutations cause the disease or predispose to the disease and are typically not present in normal peopl

Answer 2

mutations in single genes w/ large effects

Question 3

what mutations and their associated disorders are highly penetrant (presence of mutation is associated w/ disease in large proportion of individuals)

Answer 3

mutations in single genes w/ large effects

Question 4

what mutation usually follow Mendelian pattern of inheritance

Answer 4

mutations in single genes w/ large effects

Question 5

what specific DNA mutations cause large effect in gene mutation

Answer 5

deleted, inserted, and substituted

Question 6

chromosomal disorders arise from structural or numerical alterations in what??

Answer 6

autosomes and sex chromosomes

Question 7

what disorder is uncommon but associated with high penetrance

Answer 7

chromosomal disorders

Question 8

how do chromosomal disorders specifically cause mutation

Answer 8

1. single chromosome mutation - deletion, duplication, inversion
2. insertion
3. translocation

Question 9

what sis the most common genetic disorder of the three

Answer 9

complex multigenic disorders

Question 10

what causes complex multigenic disorders

Answer 10

interactions btwn multiple variant forms of genes and environmental factors

Question 11

variations in genes are common within population and are also called ___

Answer 11

polymorphism

Question 12

in complex multigenic disorders, does each variant gene confer a small increase in disease risk, and no single susceptibility to genes is necessary or sufficient to produce the disease

Answer 12

YES

Question 13

what is a permanent change in the DNA

Answer 13

mutation

Question 14

mutations affect ___ cells and are transmited to the progeny and can give rise to ___ diseases

Answer 14

germ; inherited

Question 15

mutations that affect ___ cells do not cause hereditary diseases but are important in the genesis of cancers and congenital malformations

Answer 15

SOMATIC cells

Question 16

A ___ is a change in which a single
base is substituted with a different base

Answer 16

point mutation

Question 17

sickle cell anemia is an example of what mutation

Answer 17

point mutation (valine is substituted for glutamic acid)

Question 18

types of gene mutations

Answer 18

1. point mutations within coding sequences
2. mutations within noncoding sequences
3. deletions and insertions
4. trinucleotide repeat mutations

Question 19

point mutations or deletions involving regulatory sequences may interfere with what

Answer 19

binding of transcript factors

Question 20

thalassemia is an example of what mutation

Answer 20

mutations within noncoding sequences (interfer w/ binding of transcript factors)

Question 21

what is a noncoding, intervening sequence of DNA within a gene

Answer 21

intron

Question 22

small deletions and insertions involving the coding sequence effect ___

Answer 22

the encoded proteins

Question 23

cystic fibrosis is an example of what mutation

Answer 23

deletion

Question 24

fragile X syndrome is an example of what mutation

Answer 24

insertion and trinucleotide repeat mutations

Question 25

what is characterized by amplification of sequence of three nucleotides

Answer 25

trinucleotide repeat mutations

Question 26

almost all affected sequences in trinucleotide repeat mutations share what nucleotide

Answer 26

guanine (G) and cytosine (C)

Question 27

what disease and what is this example of: there are 250 to 4000 tandem repeats of the sequence CGG within a gene called familial mental retardation 1 (FMR1); this prevents normal expression of FMR1 gene, giving rise to mental retardation

Answer 27

fragile X syndrome - example of trinucleotide repeat mutations

Question 28

Virtually all Mendelian disorders are the result of mutations in ___ that have large effects

Answer 28

single genes

Question 29

T/F: most mutations in autosomal genes produce partial expression in HOMOZYGOTE and full expression in HETEROZYGOTE

Answer 29

FALSE! most mutations in autosomal genes produce partial expression in HETEROZYGOTE and full expression in HOMOZYGOTE

Question 30

mutations involving single genes typically follow what three patterns of inheritance

Answer 30

1. autosomal dominant 2. autosomal recessive 3. X-linked