Diagnostic Genetic Tests

Diagnostic Genetic Tests

Diagnostic genetic tests are used to identify genetic disorders or mutations that may contribute to certain health conditions. Here is a list of common types of diagnostic genetic tests:

1. Carrier Screening Tests

• Used to determine if a person carries a gene for a genetic disorder that could be passed on to offspring.
• Examples: Cystic fibrosis, sickle cell anemia, Tay-Sachs disease.

2. Pre-implantation Genetic Testing (PGT)

• Performed on embryos created through in vitro fertilization (IVF) to test for genetic conditions before implantation.
• Types:
  • PGT-M: Testing for monogenic disorders (single gene defects).
  • PGT-SR: Testing for structural rearrangements in chromosomes.
  • PGT-A: Testing for aneuploidy (abnormal chromosome number).

3. Newborn Screening Tests

• Performed on newborns to detect genetic disorders that can be treated if diagnosed early.
• Examples: Phenylketonuria (PKU), cystic fibrosis, hypothyroidism.

4. Chorionic Villus Sampling (CVS)

• A prenatal test that involves taking a sample from the placenta to test for chromosomal conditions.
• Tests for conditions like Down syndrome, cystic fibrosis, and other inherited disorders.

5. Amniocentesis

• A prenatal test where a sample of amniotic fluid is taken to check for chromosomal conditions, genetic disorders, and neural tube defects.
• Commonly tests for Down syndrome, cystic fibrosis, and spina bifida.

6. Whole Exome Sequencing (WES)

• Sequencing the protein-coding regions of the genome to identify genetic mutations responsible for diseases.
• Often used for rare or undiagnosed conditions.

7. Whole Genome Sequencing (WGS)

• A more comprehensive genetic test that sequences the entire genome, providing information on both coding and non-coding regions.
• Used for diagnosing complex genetic conditions, rare diseases, and to understand genetic predispositions.

8. Fluorescence In Situ Hybridization (FISH)

• A test used to detect specific genetic abnormalities, including chromosomal deletions, duplications, or translocations.
• Commonly used for conditions like Down syndrome, chronic myelogenous leukemia, and other cancers.

9. Single Gene Tests

• Targeted tests that analyze one specific gene for mutations associated with a particular disease.
• Examples: BRCA1 and BRCA2 for breast cancer susceptibility, Huntington's disease test, Duchenne muscular dystrophy test.

10. Microarray Analysis

• Detects chromosomal abnormalities such as deletions, duplications, or other structural changes at a high resolution.
• Often used for developmental delays, autism spectrum disorders, and unexplained genetic conditions.

11. Tumor Genetic Testing

• Used to analyze genetic mutations in cancer cells.
• Types:
  • Somatic testing: Focuses on mutations acquired by the cancer cells.
  • Germline testing: Examines inherited mutations that may increase cancer risk (e.g., BRCA mutations for breast and ovarian cancer).

12. HLA Typing

• Identifies specific human leukocyte antigens for transplant matching or to assess genetic predisposition to certain autoimmune diseases.

13. Mitochondrial DNA Testing

• Detects mutations in mitochondrial DNA, which can lead to mitochondrial disorders.
• Conditions like Leber’s hereditary optic neuropathy (LHON) or MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) are tested for.

14. Autosomal Dominant/Autosomal Recessive Testing

• Used to identify mutations related to dominant or recessive inheritance patterns, such as in conditions like Marfan syndrome or sickle cell disease.

15. Genetic Testing for Drug Response (Pharmacogenomics)

• Tests how a person’s genetic makeup affects their response to drugs.
• Can help guide treatment for conditions like cancer, psychiatric disorders, and cardiovascular disease.

16. Y-Chromosome Microdeletion Testing

• Used to analyze the Y chromosome for microdeletions that may cause male infertility.

These tests help in diagnosing genetic disorders, providing insights into treatment options, and identifying risks of developing certain conditions. Always consult a genetic counselor or healthcare provider before undergoing genetic testing.