Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

GGE > Genetics 1 - Inheritance Patterns > Flashcards

Genetics 1 - Inheritance Patterns Flashcards

1
Q

essential learning outcomes

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Klippel-Feil Syndrome clinical symptoms

A

webbed neck

high arched palate

normal carrying angle

low set hairline - mid thoracic spine

congenital protrusion from skull

pectus excavatum

no organomegaly

kyphoscoliosis

significant restricted range of movement cervical and thoracic spine

SOB - minimal exertion

acute kidney injury

thoracic aortic aneurysm and thoracoabdominal aneurysm

dilation of aortic arch

bilateral pulmonary hyperinflation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what causes symptoms of Kippel-Feil Syndrome

A

congenital fusion of any 2 of 7 cervical vertebrae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Klippel-Feil Syndrome - mutations of what genes

A

GDF6

GDF3

MEOX1

(bone development)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Klippel-Feil Syndrome inheritance pattern

A

can be autosomal dominant or recessive (depends on gene involved)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Huntington disease inheritance pattern

A

autosomal dominant pattern

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

characteristics of Huntington

A

progressive neuronal loss - loss of neurons in basal ganglia

disease onset usually 30’s or 40’s

survival for 15-20 yrs after 1st symptoms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

gene associated with Huntington

what sort of mutation is it

A

HTT gene

Polyglutamine/repeat expansion mutation

Trinucleotide repeat - repeat for CAG (makes glutamine)

Multiple copies of CAG

Non functional huntington protein

The more repeats you have, the earlier you are likely to display symptoms and more severe the phenotype will be

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

anticipation of Huntington

A

offspring may have earlier onset/more severe phenotype than parent due to further expansion of the repeat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

risk for children - Huntington

A

27-35 repeats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

incomplete penetrance - Huntington

A

36-39 repeats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

no of repeats needed to develop Huntington

A

40+

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

how to screen for Huntington

A

preimplantation and prenatal diagnosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

select the non-hereditary, congenital diseases from the following list

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

rank these concepts in order of appearance

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

autosomal inheritance

A

not sex dependent

allele located on 1 of 22 autosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

X-linked inheritance

A

clear pattern of sex dependent inheritance

allele located on the X chromosome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

pedigree interpretation

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what’s the pattern of mendelian inheritance

A

recessive

neither of Alexei’s parents have the condition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

X linked recessive pattern - Mendelian inheritance

A

character is typically manifested in male offspring of UNAFFECTED offspring

not in offspring of affected males

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

X linked recessive basis - Mendelian inheritance

A

genetic locus is on an X chromosome

female has 2 X chromosomes

non-functional allele on 1 X chromosome means

  • 1 functional allele for a woman
  • no functional allele for a man
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how can a female with carrier mother display classical haemophilia A

A

de novo mutation in the “good” allele

or

daughter of haemophiliac father and carrier mother

also by UPD of maternal X or by skewed X-inactivation of paternal X

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

vit D resistant rickets also known as

inheritance pattern

A

X-linked hypophosphatemic rickets (XLH)

X linked dominant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

what is the only known Y linked character

A

maleness

50% chance that each child of an affected male will manifest the character

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what pattern of mendelian inheritance is this
autosomal recessive
26
what pattern of mendelian inheritance is this
both males and females affected so probably not X linked affected in every generation AUTOSOMAL DOMINANT
27
e.g. of a dichotomous trait
cleft chin - dominant 1 gene (MENDELIAN)
28
mendelian
1 gene involved
29
polygenic/multifactorial
character is determined by a large no of genes and the interaction of expression of those genes with the environment - not Mendelian height shoe size eye colour intelligence
30
environmental influence - trait independent of such factors
Huntington always associated with an expressed trait
31
T2D and environment
genetic predisposition to develop T2D but if one watches their diet, unlikely to develop it
32
incomplete penetrance
penetrance = probability of a genotype/trait being expressed phenotype only expressed in a fraction of the population with the genotype
33
variable expressivity
variation in phenotype expression when penetrance is complete a range of symptoms displayed in individuals with the same fully penetrant genotype
34
what happens when penetrance is incomplete but high
the disease will appear to be Mendelian but may occasionally appear to skip a generation most obvious for autosomal dominant inheritance
35
what happens when penetrance is low
mendelian patterns are often very difficult to appreciate in the absence of large extended pedigrees
36
prevalence of variable expressivity
the norm among genetic diseases and is particularly common for disorders that affect multiple organ systems
37
factors that influence penetrance and expressivity
age gender environmental risk factors lifestyle risk factors modifier genes parents of origin (epigenetic) effects
38
clinical case
39
inheritance pattern of hypercholesterolemia associated genes
dominant pattern of inheritance LDLR gene on Chr 19
40
clinical symptoms of hypercholesterolemia
skin lesions (xanthelasmata) present on eyelids and under eyes MI xanthomas
41
things to remember
42
genome
all of the hereditary info that an organism has encoded in its DNA (or for some viruses DNA)
43
chromosome
a threadlike structure of DNA and protein (chromatin) found in the nucleus of most living cells each chromosome has many genes which carry genetic info human cells have 23 pairs of chromosomes (22 autosomes + our sex chromosomes)
44
gene
unit of heredity which is transferred from a parent to offspring and is responsible for a character/trait of the offspring or a DNA sequence associated with a particular property/encoding for a particular protein
45
allele
each of 2 or more alternative forms of a gene that arise by mutation and are found at the same place (locus) on a chromosome
46
homozygous
refers to a gene with identical alleles on both homologous chromosomes
47
heterozygous
refers to a gene with different alleles on each homologous chromosome
48
phenotype
observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences
49
genotype of an organism
the entire set of allels in an organism that determines the expression of its characteristics or traits (Which allele do you have at each locus on your chromosomes)
50
trait/character
a specific part/relatively discrete element of total phenotype
51
dichotomous characters
yes/no extra fingers, presence or absence of a disease
52
quantitative/continuous characters
height IQ
53
mendelian characters synonym
specific identifiable characters/traits (normal or pathological) that show a fairly clear cut pattern of inheritance monogenic the specific character/trait depends mostly on genotype at a single gene locus given an otherwise normal genetic and environmental background 1 allele at 1 specific locus determines the character In HETEROZYGOUS state he was able to tell if traits were recessive or dominant
54
mendelian disease
Huntington 4p16.3
55
punnett square
mother is heterozygous for H allele (dominant pattern of inheritance for monogenic Huntington's disease character) father is homozygous for h allele (recessive pattern of inheritance for non HD character)
56
inheritance pattern - CF
recessive terms generally refer to pattern of inheritance of character (phenotype) rather than to the gene
57
dominant and recessive describe
functional relationship of 2 different alleles of the same gene in a (compound) heterozygous organism
58
dominant genetic characters
59
recessive genetic characters
60
fully penetrant condition
e.g. Huntington clinical phenotype is manifested in 100% of the offspring with the appropriate genotype
61
incomplete/reduced penetrance condition
e.g. breast cancer in carriers of BRCA1 and BRCA2 genes clinical phenotype is not observed among all individuals High risk for breast cancer, but not 100% guaranteed to display breast cancer
62
what influences penetrance
penetrance is a complex continuum influenced by other (modifier) genes and non-genetic factors (environment, lifestyle, age, epigenetics)
63
penetrance of mendelian conditions vs multi-factorial
Mendelian single gene conditions - more likely to be fully penetrant Multi-factorial - less than 100% penetrance
64
e.g. variable expressivity
even siblings with the same mutation for Cystic Fibrosis have varying degrees of lung and pancreas dysfunction
65
variable expressivity in neurofibromatosis type 1
66
incomplete dominance
intermediate inheritance in dominant disorders in which 1 allele is not completely expressed over its paired allele (blending of traits) clinical phenotype of MOST DOMINANT genetic traits in heterozygotes (Aa) is in-between that of wild-type (aa) and mutant homozygotes (AA) homozygosity for a disease causing mutation (AA) with dominant pattern of inheritance often results in much more severe clinical phenotype
67
e.g. incomplete dominance
e.g. achondroplasia (short limbed dwarfism) heterozygosity for FGFR3 mutation (Ff) = short limbed dwarfism homozygosity for FGFR3 mutation (FF) = stillborn/early death due to resp failure (underdeveloped ribcage)
68
clinical case - Marfan syndrome associated gene symptoms
MCQ
69
things to remember

GGE (33 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions