Genetics Flashcards
what is the backbone of DNA
sugar backbone- 2-deoxyribose
how many base pairs in the human genome
3 000 000 000
how many genes in the human genome
30 000
how many polymorphisms usually in a genome
3 000 000
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
what are the types of next generation tests
muliplex ligation dependent amplification
PCR amplification and sequencing
what tests can detect a point mutation
PCR amplification and sequencing
what genetic changes can karotype detect
aneuploidy (abnormal number of chromosomes)
chromosome translocation
deletion
what genetic changes can fish detect
deletion and microdeletion
what can mulitplex ligation dependent amplification detect
deletion of part of a gene
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
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)
does chromosome microarray array genomic hybridisation detect balanced or unbalanced chromosomal rearrangements only
UNBALANCED
what indicates a deletion in aCGH
half as much DNA
what is the most sensitive test for looking at whole chromosomes
aCGH
what does a red dot mean on fish
gene that is missing on other chromosome- deletion
what is considered the normal genome
commonest form of the gene sequence in caucasian americans
what can help indentifying polymorphisms that might be disease causing
comparing the DNA of the patient to their parents DNA
how much of genome codes are exons
1-2%
where do splice site mutations usually occur
1 or 2 bases into intron
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
what is a missense mutation
point mutation where a single bases creates a different amino acid
what is a triplet expansion mutation
where an amino acid is repeated (the cat cat sat on the mat)
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
