Lecture 19-Genomics in Diagnosis

Question 1

Indirect methods or linkage analysis did genetic analysis how?

Answer 1

A marker and a gene which is close together (physically) after meiotic recombination

Question 2

What are the methods that query (interrogate) the entire genome? (3)

Answer 2

1. Karyotype (G-banding)
2. Microarray: array CGH, SNP chip, expression arrays
3. Spectral Karyotype (paint each chromosome a different colour)

Question 3

G-band karyotype limits of resolution

Answer 3

See changes with whole chromosomes such as Trisomy 21.
Deletions must be greater than >5Mb for it to be detected this way

Deletions too small to be seen are called microdeletions/submicroscopic deletions

Question 4

FISH limits of resolution

Flourescent in situ hybridization

Answer 4

Can detect deletions bigger than 1 Mb.

he prob is long piece of DNA packed with fluorphore labels that can be seen by light microscopy

Question 5

Microarray CGH limits of resolution

Answer 5

Resolve 30kBp deletion/duplication

“Array of DNA probes that represent sequential regions of the genome separated by 50kB

Question 6

NGS (next generation sequencing) drawback

Answer 6

Bottle neck is with analysis of the data

Base pair resolution

1. Sequencing uses fluorescent dideoxy nucleotides
2. MASSIVELY PARALLEL obtainment of sequence data

Sanger sequencing uses P-32 labeled nucleotides

Question 7

How much of the genome codes for proteins?

Answer 7

Approx 1 percent

Question 8

What is targeted capturing?

Answer 8

Obtaining sequencing data from targeted selection of genes (ex: cardiovascular)