Appendix A

Terms and Abbreviations Used In This Report

ABMG American Board of Medical Genetics

ABN Advance beneficiary notice

Accuracy Closeness of the agreement between the result of a measurement and a true value of the measurand

ACMG American College of Medical Genetics

Allele One version of a gene at a given location (locus) along a chromosome

AMP Association for Molecular Pathology

Amplicon Piece of nucleic acid formed as the product of molecular amplification

Amplification In vitro enzymatic replication of a target nucleic acid (e.g., polymerase chain reaction [PCR])

ASR Analyte-specific reagent

Bidirectional sequencing A method used to determine the positions of a selected nucleotide base in a target region on both strands of a denatured duplex nucleic acid polymer

CAP College of American Pathologists

CDC Centers for Disease Control and Prevention

CLIA Clinical Laboratory Improvement Amendments of 1988

CLIAC Clinical Laboratory Improvement Advisory Committee

CLSI Clinical and Laboratory Standards Institute (formerly NCCLS)

CMS Centers for Medicare & Medicaid Services

Competency assessment Evaluation of a person's ability to perform all aspects of testing, from specimen collection to result reporting

Control material A device, material, solution, or lyophilized preparation intended for use in the quality-control process

CPT Current Procedural Terminology

CVS Chorionic villus sampling

DNA Deoxyribonucleic acid, the molecule that encodes genetic information

DTC Direct to consumer

Family history The genetic relationships and medical history of a family; also referred to as a pedigree when represented in diagram form using standardized symbols and terminology

FDA Food and Drug Administration

Founder effect The presence of gene mutation in high frequency in a specific population that arises because the gene mutation was present in a single ancestor or small number of ancestors in the founding population

Genetics The study of inheritance patterns of specific traits

Genome The complete genetic content of an organism

Genotype The genetic constitution of an organism or cell; also refers to the specific set of alleles inherited at a locus

Germline mutation The presence of an altered gene within the egg or sperm (germ cell), such that the altered gene can be passed to subsequent generations

Heterozygote A person with two different alleles at a particular locus, one on each chromosome of a pair, typically with one normal and one abnormal allele

HHS Department of Health and Human Services

HIPAA Health Insurance Portability and Accountability Act of 1996

Homozygote Person with two identical alleles at a particular locus, one on each chromosome of a pair

ICD International Classification of Disease

Informed consent process For molecular genetic testing, the process by which a person voluntarily confirms the willingness to participate in a particular test, after having been informed of all aspects of the test that are relevant to the decision to participate

LOD Lower limit of detection

Modifiers Genetic or environmental factors that might affect the expressivity (the variability of signs or symptoms that occur with a phenotype) of a genetic alteration

Mutation An alteration in a gene, which might cause a disease, be a benign alteration, or result in a normal variant

Newborn screening Testing conducted within days of birth to identify infants at increased risk for specific genetic disorders, allowing education and counseling for parents and treatment for patients to be initiated as soon as possible

NTC No-template control

Pedigree A diagram using standard symbols and terminology to indicate the genetic relationships and medical history of a family

Penetrance The proportion of persons with a mutation causing a particular disorder who exhibit clinical symptoms of the disorder

Personalized medicine Approach to medicine involving use of genomic and molecular data to better target health care, facilitate discovery and clinical testing of new products, and determine patient risk for a particular disease or condition

Phenotype The observable physical and biochemical traits resulting from of the expression of a gene; the clinical presentation of a person with a particular genotype

Polymerase chain reaction (PCR) A DNA amplification procedure that produces millions of copies of a short segment of DNA through repeated cycles of 1) denaturation, 2) annealing, and 3) elongation; a very common procedure in molecular genetic testing used to generate a sufficient quantity of DNA to perform a test (e.g., sequence analysis or mutation scanning) or as a test itself (e.g., allele-specific amplification or trinucleotide repeat quantification)

Positive predictive value The likelihood that a person with a positive test result actually has a particular gene, is affected by the gene, or will develop the disease

Precision Closeness of agreement between independent test results obtained under stipulated conditions

Private mutation A rare, disease-causing mutation occurring in a few families

Proficiency testing An external quality assessment program in which samples are periodically sent to testing sites for analysis

Quality assessment A group of activities to monitor and evaluate the entire testing process; used to help ensure that test results are reliable, improve the testing process, and promote good quality testing practices

Quality control Measures taken to detect, reduce, and correct deficiencies in a laboratory's internal analytical process prior to the release of patient results and to improve the quality of the results reported by the laboratory

Reagent A substance that produces a chemical or biological reaction with a patient specimen, allowing detection or measurement of the analyte for which the test is designed

Reference interval Interval between and including the lower reference limit through the upper reference limit of the reference population (e.g., 95% of persons presumed to be healthy [or normal])

Reportable range The range of test values over which the relationship between the instrument, kit, or measurement response of the system is shown to be valid

RNA Ribonucleic acid

SACGHS Secretary's Advisory Committee on Genetics, Health, and Society

Sequencing A procedure used to determine the order of nucleotides (base sequence) in a DNA or RNA molecule or the order of amino acids in a protein

Targeted mutation analysis Testing for one or more specific mutations

Total testing process Series of activities or workflow for performing testing; includes three major phases: preanalytic, analytic, and postanalytic

Unidirectional workflow The manner in which testing personnel and patient specimens move through the molecular amplification testing process to prevent cross-contamination

Variant Any heritable change in DNA sequence

Use of trade names and commercial sources is for identification only and does not imply endorsement by the U.S. Department of Health and Human Services. References to non-CDC sites on the Internet are provided as a service to MMWR readers and do not constitute or imply endorsement of these organizations or their programs by CDC or the U.S. Department of Health and Human Services. CDC is not responsible for the content of pages found at these sites. URL addresses listed in MMWR were current as of the date of publication.

All MMWR HTML versions of articles are electronic conversions from typeset documents. This conversion might result in character translation or format errors in the HTML version. Users are referred to the electronic PDF version (http://www.cdc.gov/mmwr) and/or the original MMWR paper copy for printable versions of official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.

**Questions or messages regarding errors in formatting should be addressed to mmwrq@cdc.gov.

Date last reviewed: 5/29/2009