Lecture 7 - Unusual Patterns of Inheritance Flashcards Preview

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Flashcards in Lecture 7 - Unusual Patterns of Inheritance Deck (29)
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1
Q

the _____ region is the segment of the X and y chromosomes located at the most distal portion of their respective p and q arms. crossing over can occur during ____ meiosis

A

pseudoautosomal (PAR),
male

ie X and Y recombination

2
Q

pseudoautosomal traits can have ___ to ____ transmission. the pseudoautosomal region of the X chromosome (is or is not) inactivated on the lyonized X in females

A

male to male;

is not

3
Q

the PAR contains the ____ ____ homeobox containing gene. need (one or 2) copies for normal stature?

A

short stature;
2

so if only 1 copy–>short stature (turner)

4
Q

pseudoautosomal _____ is a dominantly inherited skeletal defect with disproportionate short stature and deformity of the ____, due to mutation of short stature homeobox.

A

dyschondrosteosis;

forearm

5
Q

what is another gene that can undergo pseudoautosomal inheritance?

A

SRY/testis determining factor

6
Q

presence of the SRY gene on an X chromosome would cause a XX person to be phenotypically ___. the SRY gene causes production of what?

A

male (and infertile);

testis determining factor

7
Q

in ____an offspring receives 2 copies of a chromosome from one parent and no copies from the other parent

A

uniparental disomy (UPD)

8
Q

UPD:
heterodisomy (heterozygous) indicates a _____ error. Isodisomy (homozygous) indicates a ____ error or a postzygotic chromosomal ____ of one pair of chromosomes and ____ of the original pair.

A

meiosis 1;
meisos 2;
duplication;
loss

9
Q

UPD:

we often the presume the fetus was originally ___ followed by ____ of a chromosome aka ____ _____

A

trisomic;
loss;
trisomic rescue

10
Q

genomic imprinting (GI) = differential expression of alleles of a gene in ___ cells. involves a form of gene marking that is (reversible or irreversible?) ie _____ turns an allele off

A

somatic;
reversible;
hypermethylation

is a normal process

11
Q

2 diseases with genomic imprinting problems?

what chromosome are these associated with

A

prader-willi,
angelman;

both on chrom 15

12
Q

2 reproductive disease than may be caused by imprinting

A

complete hydatidiform mole;

ovarian teratoma

13
Q

complete hydatidiform mole = ____ genomes only;

ovarian teratoma = ____ genomes only

A

paternal, maternal

14
Q

prader willi syndrome (PWS):

the ____ imprinted gene is normally silent. the ____ gene is mutated or deleted

A

maternal;

Paternal (P for PWS)

15
Q

PWS symptoms:
hyper____, ____, intellectual disability or no?;
____ gonads; ___tonia

A

phagia, obesity, intellectual disability (moderate);
small, hypo

also short stature

16
Q

25% of cases of PWS are caused by ____ ___ _____

A

maternal uniparental disomy (ie both chromes from mom)

17
Q
angelman syndrome (AMS):
the \_\_\_\_ imprinted gene is normally silent. 
the \_\_\_\_ gene is mutated or deleted
A

paternal;

maternal (Maternal for Man)

18
Q

AMS:
aka “____ ____” syndrome. inappropriate ____, intellectual disability or no?;
sizures, ataxia

A

happy puppet;
laughter;
yes (severe)

19
Q

AMS:
5% cases due to ____ ____ ____;
other cases are due to mutation in UBE3A, which codes for ______

A

parental uniparental disomy (ie both chromes from dad);

ubiquitin-protein ligase

20
Q

AMS:

UBE3A is usually only expressed in the ____ (ie tissue specific)

A

brain

21
Q

imprinting:
occurs before or after fertilization?
must be ____ and is (reversible or irreversible) on passage through the opposite sex

A

before;
erased, reversible

ie male sperm doesn’t pass maternally imprinted chrome to male gametes (See ppt)

22
Q

mitochondria DNA:
lacks ____ and ____ = increased mutation rate;
inheritance is ____;
DNA is ____

A

proofreading, DNA-repair;
MATERNAL;
circular

23
Q

mitochondrial myopathies:
usually disorders of ____;
present with myopathy, ____ ____, and ___ probs

A

Oxidative phosphorylation;

lactic acidosis, CNS

24
Q

_____ is the presence of both normal and mutated mtDNA in a cell, resulting in _____ expression of disease

A

heteroplasmy;
variable

homoplasmy is when you get all of same kind of mtDNA in a cell

25
Q

____ ____ means that MtDNA is sorted randomly and mitochonria also distribute randomly

A

replicative segregation

26
Q

the ____ ____: impact of mutation varies depending on the tissue, the timing, and the number of mutant mitochondrial per cell

A

threshold effect

27
Q

____ ____ = number of mtDNA is reduced then amplified in the mature oocyte

A

genetic bottleneck

28
Q

“ragged red fibers” are often seen in what mitochondrial disorder?

this is due to to decreased charged ___ = increased ____ _____

A

Myoclonic epilepsy with ragged red fibers = MERRF;
tRNA;
chain termination

29
Q

MERRF causes myopathy, ____ seizures, ____ (CNS thing), and ____ (sensory thing)

A

myoclonic;
dementia;
deafness