2015 molecular medicine dna lab write up for week 2

8/17/2019 2015 Molecular Medicine Dna Lab Write Up for Week 2

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2015 MOLECULAR MEDICINE DNA LAB WRITE UP FOR WEEK 2

Name: Garrett Mcfara!e ID" #200$$%&'Date: Oct()er &* 2015C(+r,e: M(ec+ar Me-.c.!e

Gr(+/ " a!- Gr(+/: Gr(+/, * MBBT.te (f La): Ge!t.c, a)* /ater!.t te,t.!3

ANWER4 ECTION A GENETIC6:

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a. Karyotyping can be described as a technique used to analyse an

individual’s chromosomes to ascertain whether or not any chromosomalanomalies are present which may result in a genetic condition. In

karyotyping, an image of person’s chromosomes is displayed in

homologous pairs and compared to a normal set of chromosomes to

determine if there is any genetic anomaly such as monosomy or trisomy.b. Two chromosomal characteristics that are paid attention to are the length

and the position of the centromeres.c. Two dierences that maybe observed are dierences in the position of

centromeres and dierences in relative sie of chromosomes.

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a. The steps involved are denaturation, annealing and e!tension"elongation.

In the denaturation step the reaction is heated to a temperature of #$%#&

'(. This causes melting"denaturing of the )*+ template by disrupting the

hydrogen bonds between complementary bases, which results in single%

stranded )*+ molecules. In the annealing step the temperature is lowed

to -%'( for appro!imately $- seconds to allow for primers to bind to

their complementary )*+ sequences in the )*+ sample. In the e!tension

phase reaction is then heated to /0' (, which is the optimal temperature

for )*+ polymerase to act. )*+ polymerase then e!tends the primers,

adding nucleotides onto the primer in a sequential manner, using the

target )*+ as a template.b. 1our ma2or reaction components are )enature )*+, primer, a buer and

)*+ polymerase. )*+ polymerase is an enyme that creates a new strand

of )*+ through the sequential addition of nucleotides. + 3uer is a salt%


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solution that helps to stabilie the )*+ and other components of the

reaction.c. 4ne advantage is that it grants the ability to rapidly identify organisms

that are di5cult to culture, another advantage is that 6(7 tests can be

performed quickly and interpreted the same day as sample submission.

4ne disadvantage is that, since 6(7 is e!tremely sensitive, it is prone to

contaminating )*+ which can lead to erroneous results. +nother

disadvantage is that 6(7 ampli8cation is sensitive to certain inhibitors that

may be present in the )*+ preparation, an e!ample of this is phenolics.

7+e,t.(! %

a. Three characteristics that make it suitable are9 The smaller sie of :T7

alleles which make :T7 markers better for use in forensic s, they are easily

ampli8ed by polymerase chain reaction ;6(7< without the issue of

dierential ampli8cation and :T7 alleles tend to have lower mutation

rates, which allows for more accurate data and results.b. +n earlier method to )*+ 8ngerprinting and also a common method for

8ngerprinting is restriction fragment length polymorphism in this method,

)*+ is e!tracted from a sample and cut into segments using restriction

enymes, these segments are then separated using a technique known as

electrophoresis which is used in laboratories in order to separate

macromolecules based on length. The segments are radioactively tagged

to produce a visual pattern known as an autoradiograph, or )*+

8ngerprint.

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a. The gender of the individual would be male as presence of the =

chromosome indicates the person is of the male gender. To be

considered male genetically, an > and = chromosome are required,

where as a female would not have a = chromosome and therefore

cannot be the gender of the person in question.b. The se! of the individual is female, as the > speci8c markers

)>&-? and >@67T recorded two peaks, indicating the presence of

two > chromosomes which is an indication of a female. The marker

)>AA&/ also detected an > chromosome. There seems to be no

abnormality so this is a normal female ;no aneuploidy


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c. >@67T is a short tandem repeat ;:T7< marker which is >%speci8c.

;used for detecting the > chromosome4 1emale Turner

syndrome

:e! organs donDt matureat adolescence, sterility,

short statureEonosom

y $p"deletion

$p

Eale"1emale

Folf%@irschhornsyndrome

1acial appearance,delayed growth and

development, intellectualdisability, and seiures.

Trisomy0A" ?rd

copy of chromoso

me 0A

Eale"1emale

)own’s:yndrome

1lattened nose, stuntedgrowth, Gat head

)eletionof a

terminalregion of chromoso

me AA

Eale"1emale

Hacobsen:yndrome

ow%platelets, Fide%

set eyes, @eart

defects, )isplaced

receding chin

>>> 1emale trisomy >Increased risk of delayedlanguage development,

tall stature

REULT 4 ECTION B PATERNIT9 TETING 16

TABLE 8OWING ALLELE FOR C8ILD AND ALLEGED FAT8ER FORPECIFIC LOCI Ca,e A6

oci (hild +lleged 1ather)A?:?A/ &.A,A0 #, A0JF+ A?, A A, A&)A:?# #, AA AA

T64> , A- &, #):&A& A-, A? A-, A?


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TABLE 8OWING ALLELE FOR C8ILD AND ALLEGED FAT8ER FOR

PECIFIC LOCI Ca,e B6

oci (hild +lleged 1ather)A?:?A/ AA, A? AA, AJF+ A A, 0-)A:?# A0, A? A?, A$

T64> , & , &):&A& A0 A0

TABLE DIPLA9ING ALLELE OF C8ILD AND ALLEDGED FAT8ER AND

PATERNIT9 INDE FOR EAC8 LOCI Ca,e B6

oci (hild +lleged

1ather

:hared

+llele

1requenc

y of

:hared

+llele

1ormula 6aternity

Inde!

)A?:?A/ AA,A? AA,A AA -.0?/$? A"$q A.-?JF+ A A,0- A -.0#$$ A"0q A.&)A:?# A0,A? A?,A$ A? -.A-/ A"$q A.A

T64> ,& ,& ,& -.-&A0,

-.?&$0

;pq


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)*+ pro8le% This can be de8ned as the set of values of a group ofgenetic markers identi8ed in an individualDs )*+ by a processknown as )*+ pro8ling

• @eteroygote can be de8ned as a situation in which an individual has two

dierent alleles of a particular gene or genes.

6aternity inde! is a statistical measure of how powerfully a match at a particulamarker indicates6aternityP it calculates the likelihood that the tested man is the

biological father based on that loci.

7+e,t.(! F

4ne factor that may increase the likelihood of a mutation occurring is e!posure

to large amounts of ultraviolet radiation. Qltraviolet light may cause two

pyrimidine bases ad2acent to each other on the same strand to bind to each

other, instead of binding to their rightful partner on the opposite strandP this is

called a pyrimidine dimer. In order to 8! this error a process known as the

e!cision repair takes place but this process may result in a )*+ mutation.

+nother more natural or biological factor that may result in )*+ mutation is

errors by the enyme )*+ polymerase which is involved in replication. )uring

this process although it is a highly precise one, there can be mispairing of

nucleotides which can result in eventual mutation as a result of errors made bythe enyme. These two factors may lead to mutations such as deletion, frame

shift, insertion, point, translocation, silent etc.

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The alleged father in this case is not likely the father of the child presented, this is because in

locis D18S5, D13S317 and D3S1358 there are no shared alleles between the father and child. n cases

like this it is highly unlikely that the alleged would be father as there are too !any incidences of

!is!atching alleles, which cannot be attributed to !utations alone. "hen calculating the #$, the

inde%es of &.&&& would result in the #$ being & and conse'uently there being a &.&&( probability of

paternity.


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OURCE

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2015 molecular medicine dna lab write up for week 2

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