Last updated
28 Nov 2025
Genomic testing encompasses several different laboratory techniques depending on the reason for testing and what genetic material needs to be investigated.
For example, it may be necessary to only look at one gene, a few genes, the exome or the genome.
Your healthcare professional will know which one is the best test for you to have depending on your health care needs. Sometimes, you may need more than one type of genomic test.
A non-exhaustive list of types of genomic tests is provided in the table below.
| Test | Description |
|---|---|
| Single variant test | Testing for a known genetic variant in a specific gene, e.g. cascade testing for sickle cell disease |
| Single gene test | Testing for variants in a single gene, e.g. diagnostic testing for cystic fibrosis |
| Gene panel | Examines multiple genes that could be responsible for a genetic condition in a single test, e.g. gene panel testing for lung cancer |
| Fluorescence in situ hybridisation (FISH) | Testing for specific changes in genes and can be used to count the number of copies of a gene or fusions of two genes, e.g. BCR-ABL1 gene fusion in chronic myeloid leukaemia |
| Karyotyping | Low-resolution view of all chromosomes that can detect changes in chromosome number and large rearrangements of chromosomes, e.g. investigation of infertility |
| SNP microarray | High-resolution view of chromosomes that can detect changes in chromosome number and small gains or losses of chromosome material, e.g. prenatal diagnosis |
| Exome sequencing | Comprehensively determine the DNA sequence of coding regions across the genome |
| Whole genome sequencing | Determine the DNA sequence of the whole genome, including all genes and non-coding regions |
| Trio exome / genome sequencing | Comprehensively determine the DNA sequence of coding regions / the whole genome, also including samples from the patient’s biological parents to help identify which variants are more likely to be relevant to the patient’s condition, e.g. a novel or ‘de novo’ variant not inherited from either parent |
| RNA sequencing | Determine the sequence of pieces of RNA, to test for when and how genes are being expressed |
| DNA methylation | Measure levels of DNA methylation, a type of epigenetic modification attached to DNA, to understand levels of gene expression independent of the actual gene sequence |