non-mendelian

Question 1

any pattern of inheritance in which traits do not segregate in accordance with Mendel’s laws

Answer 1

non-mendelian inheritance

Question 2

examples of non-mendelian inheritance

Answer 2

• mitochondrial
• trinucleotide repeats
• mosaicism
• Genomic imprinting
• multifactorial
• chromosomal

Question 3

maternal inheritance

Answer 3

mitochondria. only mitochondria from oocyte contribute to zygote

Question 4

MELAS

Answer 4

Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-like episodes

Question 5

common features of MELAS

Answer 5

hearing loss, diabetes, seizures, intellectual disability, cardiomyopathy

Question 6

mixture of normal and abnormal mtDNA

Answer 6

heteroplasmy

Question 7

all mtDNA is the same

Answer 7

Homoplasmy

Question 8

a certain percentage of abnormal mtDNA is tolerated without symptoms

Answer 8

threshold effect

Question 9

how can the percentage of abnormal mtDNA can change over time

Answer 9

random genetic drift, and selective advantage

Question 10

____ function decreases with age

Answer 10

mitochondrial

Question 11

tissues with high energy requirements are most likely to be affected (brain, muscle…)

Answer 11

mitochondrial diseases

Question 12

usually are stable during mitosis and meiosis and are present throughout the genome

Answer 12

trinucleotide repeats

Question 13

sequence copy number is transmitted as ____________ from parent to child in trinucleotide repeat disorders

Answer 13

polymorphism

Question 14

increasing severity or earlier onset of a phenotype in successive generations

Answer 14

anticipation

Question 15

_______ relationship between repeat copy number and severity of phenotype

Answer 15

direct

Question 16

example of anticipation

Answer 16

myotonic dystrophy, fragile x syndrome, Huntington’s

Question 17

myotonic dystrophy

Answer 17

affects skeletal and smooth muscle as well as the eye, heart, endocrine system, and CNS

Question 18

sustained muscle contraction

Answer 18

myotonia

Question 19

spectrum of severity (5)

Answer 19

normal
premutation
mild 
classic
 congenital

Question 20

most common inherited cause of intellectual disability

Answer 20

fragile x syndrome

Question 21

caused by CGG repeat expansion in FMR1 gene on X chromosome

Answer 21

fragile X syndrome

Question 22

the severity of intellectual disability does or does not increase with repeat size (Fragile X)

Answer 22

does not

Question 23

female carriers in fragile x have increased risk of

Answer 23

premature ovarian insufficiency

Question 24

males who have fragile x are at risk for

Answer 24

associated tremors and ataxia syndrome (fxtas)

Question 25

Presence of more than one cell line in an individual

Answer 25

mosaicim

Question 26

two types of mosaicism

Answer 26

gonadal | somatic

Question 27

usually caused by a post-zygotic mutation and can cause a variable degree of disease severity

Answer 27

somatic mosaicism

Question 28

may be less severely affected than individuals with full trisomy 21

Answer 28

mosaic down syndrome

Question 29

True or False: | some disorders are only seen in mosaic form because the non-mosaic form is lethal

Answer 29

true

Question 30

example of a lethal form of mosaicism

Answer 30

pallister-killian syndrome

Question 31

mosaic tetrasomy 12p

Answer 31

pallister-killian syndrome

Question 32

pallister-killian syndrome characteristics

Answer 32

low muscle tone, characteristic facies, high arched palate, hypopigmentation, supernumerary nipples, developmental delays, diaphragmatic hernias

Question 33

_____ mosaicism individual unaffected with the condition

Answer 33

gonadal

Question 34

mutation occurred in precursor egg or sperm cell

Answer 34

gonadal mosaicism

Question 35

why is gonadal mosaicism important for recurrence risk assessment?

Answer 35

for apparently de novo dominant disorders

Question 36

inferred when at least two offspring have an autosomal dominant disorder with no other family history

Answer 36

Gonadal mosaicism

Question 37

true or false: | you can test for individual sperm/eggs for gonadal mosaicism

Answer 37

false

Question 38

the difference epigenetic modification on the maternal and paternal genetic contributions to the zygote

Answer 38

imprinting

Question 39

genomic imprinting mechanisms

Answer 39

uniparental disomy heterozygous deletion mutation

Question 40

methylation of the gene results in

Answer 40

no protein

Question 41

imprinting reset before

Answer 41

oogenesis or spermatogenesis

Question 42

_____ is evidence for imprinting

Answer 42

triploidy

Question 43

the presence of three sets of chromosomes instead of the usual two

Answer 43

triploidy

Question 44

two sets of maternal chromosomes and one set of paternal chromosomes

Answer 44

digynic triploidy

Question 45

two sets of paternal chromosomes and one set of maternal chromosomes

Answer 45

diandric triploidy

Question 46

ver small fetus and placenta

Answer 46

digynic triploidy

Question 47

normal to small fetus with a large cystic placenta

Answer 47

diandric triploidy

Question 48

evidence of uniparental disomy

Answer 48

cystic fibrosis

Question 49

possible explanations of uniparental disomy

Answer 49

non-paternity de novo mutation large deletion on paternal chromosome maternal uniparental disomy

Question 50

growth disorder with prenatal onset

Answer 50

russell silver syndrome

Question 51

examples of uniparental disomy and imprinting

Answer 51

russell silver

Question 52

true or false: not all uniparental disomy results in a phenotype

Answer 52

true

Question 53

paternal UPD

Answer 53

6, 11, 14, 15

Question 54

maternal UPD

Answer 54

7, 14, 15, 16

Question 55

caused by lack of expression from genes in the critical region that are normally expressed from the paternal allele

Answer 55

Prader- Willi syndrome

Question 56

Prader-willi

Answer 56

pathological overeating (hyperhagia), hypotonia, intellectual disability

Question 57

caused by lack of expression from genes in the critical region that are normally only expressed from the the maternal allele

Answer 57

Angelman

Question 58

Angelman syndrome

Answer 58

severe intellectual disability, movement disorder, seizures

Question 59

Hypotheses as for why does mitochondrial function decrease with age?

Answer 59

* Damage to mtDNA from free radicals due to ox phos | * Increased mutation rate due to lack of repair