DNA variants and sequencing & Risk is not a certain prediction

DNA variants and sequencing

Genetic tests identify changes in DNA, often called variants. Many genes provide instructions for proteins. Most changes have no effect, but some contribute to disease. Testing can examine genes, chromosomes, or protein amount and activity. Genome sequencing examines all DNA; exome sequencing focuses on regions with protein-making instructions. Chromosomes package DNA with proteins, and people usually have 23 pairs containing hereditary information. Testing can help diagnose disease, identify carrier status, or estimate increased risk.

Risk is not a certain prediction

Testing can help diagnose disease, identify carrier status, or estimate increased risk. Prenatal tests and newborn screening address different life stages. A result may not predict whether symptoms will appear, their severity, or future progression. Findings may be uncertain or reveal unexpected risks unrelated to the original question. A variant therefore must be interpreted in context rather than treated as a complete forecast of health.

Key concepts

DNA variants and sequencing

Genetic tests identify changes in DNA, often called variants.

Risk is not a certain prediction

Testing can help diagnose disease, identify carrier status, or estimate increased risk.

Samples and genetic counseling

Tests commonly use blood or cheek swabs; other samples may include saliva, skin, or amniotic fluid.

Using results in care decisions

Increased risk may lead to earlier or more frequent screening, monitoring, or health-behavior changes.

References

• MedlinePlus en español — DNA and Genetic Testing