Diagnostic Genomic Testing
Overview
Diagnostic genomic testing, also known as genetic testing or molecular diagnostics, involves analyzing an individual's DNA to identify genetic variations that may be associated with specific diseases or conditions. This type of testing is crucial for diagnosing genetic disorders, understanding the genetic basis of diseases, and guiding treatment decisions.
What is Diagnostic Genomic Testing?
Diagnostic genomic testing examines an individual's genetic material—DNA, RNA, chromosomes, or proteins—to identify changes or mutations that could be causing a disease or condition. These tests can detect single nucleotide polymorphisms (SNPs), insertions, deletions, copy number variations, and other genetic abnormalities.
Types of Diagnostic Genomic Tests
Single Gene Testing
Purpose
Focuses on one specific gene to identify mutations associated with a known condition.
Example: Testing the CFTR gene for cystic fibrosis.
Panel Testing
Purpose
Analyzes multiple genes at once, usually those known to be associated with a particular condition or group.
Example: Cancer panels that test for mutations in BRCA1, BRCA2.
Exome Sequencing
Purpose
Sequences all the protein-coding regions of genes (exons) to identify rare genetic variants.
Example: Identifying mutations that cause rare genetic disorders.
Whole Genome Sequencing
Purpose
Sequences the entire genome to provide comprehensive information about all genetic variations.
Example: Used in complex cases where other tests have not provided a diagnosis.
Chromosomal Microarray Analysis
Purpose
Detects large-scale chromosomal changes, such as duplications or deletions.
Example: Diagnosing developmental disorders and congenital anomalies..
RNA Sequencing
Purpose
Analyzes gene expression patterns by sequencing RNA.
Example: Used in cancer diagnostics to understand tumor behavior.
Applications of Diagnostic Genomic Testing
Inherited Genetic Disorders
Diagnoses conditions such as cystic fibrosis, sickle cell anemia, and Huntington's disease.
Cancer Diagnostics
Identifies genetic mutations in tumors to guide targeted therapy and personalized treatment plans.
Neurological Disorders
Diagnoses conditions like epilepsy, muscular dystrophy, and hereditary neuropathies.
Cardiovascular Diseases
Detects genetic mutations associated with conditions such as cardiomyopathy and arrhythmias.
Prenatal and Perinatal Testing
Screens for genetic abnormalities in embryos, fetuses, and newborns.
Process of Diagnostic Genomic Testing
Sample Collection
Samples can include blood, saliva, cheek swabs, amniotic fluid, or tissue biopsies.
Laboratory Analysis
Bioinformatics tools are used to interpret the data and identify genetic variations.
Benefits of Diagnostic Genomic Testing
Family Planning
Informs family members about potential genetic risks and inheritance patterns.