In plain words
Carrier screening is a blood or saliva test that looks for changes in genes linked to inherited conditions. Most people carry a few such changes without any health effects. A carrier has one copy of a changed gene. A condition usually appears only when a child inherits two changed copies, one from each parent. Screening can show whether both partners carry a change for the same condition. Many people are offered it before pregnancy or early in pregnancy. The results can guide the next step, such as a visit with a genetic counselor or more testing. A carrier result does not mean a child will have the condition. It describes a possibility that depends on the partner's results too.
The deeper version
Carrier screening tests for pathogenic variants in autosomal recessive and X-linked genes, ranging from targeted tests for specific ancestries or conditions to expanded panels covering hundreds of genes. ACOG Committee Opinions No. 690 and No. 691 (2017) describe offering carrier screening, ideally before pregnancy, with attention to ancestry, family history, and pretest counseling. Detection rates differ by ancestry and panel, and residual risk after a negative result is not zero, particularly for variants not on the panel. Expanded panels raise questions about incidental findings and about variants of uncertain significance. A joint statement from the ACMG, ACOG, and other groups (Edwards and colleagues, 2015) lists points to consider on expanded carrier screening, and professional bodies differ on how broad panels should be offered.
Where it comes up
- The preconception visitBefore Pregnancy
- Prenatal tests and ultrasounds: what each one isPregnancy: Your Body
- Trimester Zero: preparing your body before pregnancyBefore Pregnancy
- Pregnancy at 35 and olderPregnancy: Your Body
- Trying to conceive: how long is normal, when to ask for helpBefore Pregnancy
What mothers here say about carrier screening
No one has posted under this term yet.
Sources
- American College of Obstetricians and Gynecologists — Committee Opinion No. 690: Carrier Screening for Genetic Conditions, 2017
- American College of Obstetricians and Gynecologists — Committee Opinion No. 691: Carrier Screening in the Age of Genomic Medicine, 2017