Genetic diagnosis by PCR

Purpose of Assessment

To provide an update on the utility and applications of PCR technology in medicine. Economic and ethical aspects of PCR are also considered.

Methods

Narrative review, Cost analysis, State of the art report at early stage of development

Primary Data Collection

Questionnaire survey of 13 institutions and laboratories in Sweden to study the use of PCR in health care.

Basis for selection of data; type of study included

Computerized literature searches including Medline and other Swedish databases.

Review process for the publication

Internal review by project group, SBU Board and SBU Expert Group. Additional external review by experts in the field.

Content of Report

PCR (Polymerase Chain Reaction), a gene amplification technique, is currently the most well known of the genetic diagnostic methods. The results of the survey confirm that PCR technology has already disseminated widely in health care. PCR is used routinely in many places, but almost always as a complement to other diagnostic methods.

Inherited Disease – In about 80% of suspected cases for genetic disease, PCR has replaced conventional diagnostic methods for determining hemophilia, alpha -1- antitrypsin deficiency, phenylketonuria, cystic fibrosis, and Duchennes muscular dystrophy. In the future, PCR technology will make it possible for more comprehensive genetic counselling and to track genetic risk factors for some cardiovascular diseases and psychological disorders.

Infectious Disease – Diagnosis of HIV and tuberculosis was identified as suitable for PCR technology, but antibody testing continues to be the most common method of diagnosis. Current tests for herpes simplex, hepatitis C, and papillomavirus may be completely replaced by PCR technology.

Tissue Typing – PCR is expected to enter routine clinical use for tissue typing. PCR was perceived to be more sensitive, and exact than current methods.

Cancer Diagnosis – PCR is expected to complement, not replace, current methods, particularly classification of cells to determine the spread of cancer. PCR is felt to be more sensitive, faster and less expensive.

Forensic Medicine – It is anticipated that PCR will be used in approximately 50% of all examinations. It is faster and more sensitive than other methods. Economic Aspects - Laboratory costs are expected to increase with use of PCR.

Medical Benefits – It is expected that PCR will provide better information for diagnosis and improve the ability to evaluate different treatment methods.

Problems – Because PCR is extremely sensitive, there is a risk for an increased number of inaccurate results. PCR raises a number of ethical issues relating to amniocentesis, confidentiality, and personal integrity.