Laboratory Selection in Germline Genetic Testing: Laboratory Science Matters

There are multiple laboratories that offer germline genetic testing, and it can be difficult to discern which one to use for testing. Some laboratories have more comprehensive analysis techniques and capability, which increases the accuracy of testing. The ordering provider has a responsibility to select the appropriate laboratory with technologic capability for the needed testing, inform the laboratory of prior testing results in the patient and family so known familial variants have targeted testing, and use appropriate terminology and nomenclature when communicating information to other healthcare professionals, patients, and families. This report presents a case illustrating the potential errors that can occur when a provider selects a laboratory that lacks the capacity to detect certain pathogenic variants, such as large deletions and duplications. False-negative germline testing results lead to missed opportunities in prevention and early detection for not only the patient but often multiple family members, which may lead to psychosocial distress and late-detected cancers. This case highlights the complexities of genetic care and why management by a genetics professional can facilitate more fiscally responsible care, appropriate genetic testing, and comprehensive care for all family members at risk.