Introduction to Genetic Testing and Sequencing

Genetic testing DTC (direct to consumer) Clinical genetic testing overseen by clinician. Diagnosis / screening pre-birth / after birth / tailoring treatments / etc.

Genetic disease - starts from the nucleus, but depends on what happens downstream. Sequencing isn’t the only answer. E.g. chromosomes vs nucleotides. Chromosomal genotyping to see chromosomal issues but with greater resolution, and genetic microarrays to characterize known genes. WGS for identifying novel conditions.

Traditional

  • Karyotype - overall structure and number only
  • FISH - look at regions of chromosomes

Microarray

  • Chromosomal microarray - Detect chromosomal abnormalties at a higher resolution
  • Genotyping array - SNPs. Commonly in Direct to Consumer testing

Sequencing

  • Single gene
  • Gene panel
  • Exome
  • Whole genome - cost prohibitive

Functional test (measure the function of a type of change)

  • Biochemical assay - levels of proteins / metabolites in individual
  • DNA methylation assay - epigenetic variation
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