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Flashcards in Genetics Deck (27):
1

what is the backbone of DNA

sugar backbone- 2-deoxyribose

2

how many base pairs in the human genome

3 000 000 000

3

how many genes in the human genome

30 000

4

how many polymorphisms usually in a genome

3 000 000

5

what tests does array genomic hydridisation tests (aCGH) include and what do they test

standard kaytotype- entire chromosome

FISH- 5-10 megabases

multiplex ligation dependent amplification- 1000 bases

6

what are the types of next generation tests

muliplex ligation dependent amplification

PCR amplification and sequencing

7

what tests can detect a point mutation

PCR amplification and sequencing

8

what genetic changes can karotype detect

aneuploidy (abnormal number of chromosomes)

chromosome translocation

deletion

9

what genetic changes can fish detect

deletion and microdeletion

10

what can mulitplex ligation dependent amplification detect

deletion of part of a gene

11

what is the difference between a balanced and an unbalanced chromosomal translocation

balanced- even exchange of material with no genetic information extra or missing

unbalanced- unequal transition causing extra or missing genes

12

what does chromosome microarray array genomic hybridisation let you see

sub microscopic deletions/ duplications of chromosomal material across the whole genome

compares control DNA to patients (half as much= deletion, 50% more= duplication)

13

does chromosome microarray array genomic hybridisation detect balanced or unbalanced chromosomal rearrangements only

UNBALANCED

14

what indicates a deletion in aCGH

half as much DNA

15

what is the most sensitive test for looking at whole chromosomes

aCGH

16

what does a red dot mean on fish

gene that is missing on other chromosome- deletion

17

what is considered the normal genome

commonest form of the gene sequence in caucasian americans

18

what can help indentifying polymorphisms that might be disease causing

comparing the DNA of the patient to their parents DNA

19

how much of genome codes are exons

1-2%

20

where do splice site mutations usually occur

1 or 2 bases into intron

21

how do you know that a polymorphism is disease causing

in gene that matches phenotype
has affect on gene function
not listed as a polymorphism (in significant amount in population)
it is an evolutionary conserved bit of gene
it is de novo in child
or is present in affected family members

22

what is a missense mutation

point mutation where a single bases creates a different amino acid

23

what is a triplet expansion mutation

where an amino acid is repeated (the cat cat sat on the mat)

24

what are the features of kabuki make up syndrome

speech delay
cleft palate
unusual eyes and eyebrows
tendency to drool
short 2nd phalange of 5th finger

25

what is the best test to identify de novo mutations in a child

next generation sequencing (can also test parents to exclude variants)

26

what is the biggest cause of mutations in a child

increase in paternal age (age of father)

27

what does tuberous sclerosis cause

seizures