Module 6: Genetic Testing Methodologies & Applications

Question 1

Genetic testing methodologies in cytogenetics

Answer 1

• Chromosomes
• FISH
• Genomic Microarrays

Question 2

Genetic testing methodologies in molecular genetics

Answer 2

DNA sequencing:

• Panels of genes
• One gene at a time
• Genome Wide Association Studies (GWAS)
• Sanger sequencing
• Whole genome sequencing
• Whole exome sequencing

Question 3

Genetic Testing Methodologies in Biochemical Testing

Answer 3

Analyte testing

Question 4

Chromosome Banding

Answer 4

Gives karyotypes

Question 5

Fluorescently In Situ Hybridization (FISH)

Answer 5

• Fluorescently labeled DNA probes for specific regions of the chromosome
• Higher resolution than G-banded chromosomes
• Metaphase or Interphase cells

Question 6

What are the goals of Molecular Testing

Answer 6

• Identify single gene disorders
• Identify polymorphisms (SNP’s, Copy number variants, etc.)
• Identify very small duplications, deletions, & expansions in the DNA that cannot be detected by cytogenetics

Question 7

DNA Sequencing

Answer 7

• Can be used as a screening or diagnostic test
• Single gene testing
• Gene panels – multiple genes tested at the same time
• GWAS – polygenic risk scores
• Technical limitations-not all gene mutations can be identified or classified

Question 8

Direct to Consumer Genetic Testing

Answer 8

• Use molecular genetics technology

- Often a limited subset of markers are evaluated (genotyping)

Question 9

Biochemical Genetic Testing

Answer 9

• Can be influenced by many disease processes
• Often does not identify carriers
• Does not directly test the gene(s) involved
• Evaluation of enzyme substrates, products and activities