Trio testing to improve diagnostic yield in exome and genome sequencing

Trio testing analyzes DNA from the patient alongside two first-degree relatives, typically the biological mother and father, to provide a more complete genetic picture.

Parental samples are used solely to support interpretation of the patient’s results and are not evaluated or reported independently.

By comparing variants across all three individuals, clinicians can better determine whether a variant is inherited or de novo—improving diagnostic clarity and confidence.

Trio exome sequencing analyzes the protein-coding regions of DNA from a patient and both parents. Including parental samples helps improve variant interpretation, which can increase diagnostic yield and reduce inconclusive findings compared to proband-only testing.

Trio testing may be considered when evaluating patients with suspected genetic conditions, particularly when identifying de novo variants is important for diagnosis or when prior testing has been inconclusive.

It is often recommended when a more comprehensive and efficient diagnostic approach is needed.

Trio testing includes the patient and both parents, providing the most context for variant interpretation. Duo testing includes the patient and one parent. Proband-only testing analyzes only the patient.

Including parental samples generally improves diagnostic yield and reduces inconclusive results compared to proband-only approaches.

Yes. Including parental samples in trio testing can increase diagnostic yield by providing additional context for variant interpretation, particularly when identifying de novo variants.

This added context can help reduce inconclusive findings and support more confident clinical decision-making.