Diagnostic tests for genetic and chromosomal disorders

Karyotyping: This involves the examination of a person’s chromosomes in a sample of cells. This test can identify genetic disorders through the visibility of abnormalities in the size, shape, or number of chromosomes.
Polymerase Chain Reaction (PCR): This is a laboratory technique used to make multiple copies of a segment of DNA. It’s often used in diagnostic tests to amplify and then examine particular segments of the DNA for mutations.
DNA Sequencing: This is used to determine the precise order of the bases in a DNA molecule. It allows for the identification of mutations in the DNA sequence that may lead to genetic disorders.
Gene Tests: These tests investigate specific genes or short lengths of DNA to identify abnormalities that may result in a genetic disorder.

Fluorescent in Situ Hybridization (FISH): This test visualises how genes or chromosomes are altered in cells or tissues. It uses fluorescent probes that bind to only those parts of the chromosome with which they are homologous.
Comparative Genomic Hybridization (CGH): This technique involves the comparison of a patient’s DNA with a normal reference DNA. It’s used to find regions of DNA which are gain (duplicated) or lost (deleted) in the patient’s DNA.
Chromosomal Microarray (CMA): Also known as array comparative genomic hybridization (aCGH), this test can identify large scale alterations in the genome such as deletions, duplications or rearrangements which can lead to a chromosomal disorder.

Carrier screening: This is a type of genetic test that can tell you whether you carry a gene for certain inherited disorders. It’s useful for individuals with a family history of a genetic condition or for people in certain ethnic groups with an increased risk of specific genetic conditions.

Tumour DNA Sequencing: This is the sequencing of the tumour’s DNA to identify potential genetic changes causing the cancer. It’s useful for understanding the genetic basis of the patient’s cancer and could guide treatment decisions.
Inherited Cancer Panel Tests: These are blood tests that can detect inherited gene mutations which increase the risk of developing certain types of cancer. These tests can be vital for people who have a strong family history of a certain disease, such as breast or colon cancer.