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Cystic fibrosis carrier:
what it means for your kids.

About 1 in 25 white Americans carries a cystic fibrosis gene, and nearly all of them are healthy and unaware. Here's what being a carrier means, your odds by ancestry, and how couples check.

By the DontMarryYourBro team · Updated October 2026 · 5 min read · How we fact-check

The short answer

  • CF carriers are healthy. They have one altered CFTR gene and one working copy.
  • Carrier odds: about 1 in 24 Ashkenazi Jewish, 1 in 25 white, 1 in 58 Hispanic, 1 in 61 Black and 1 in 94 Asian Americans.
  • If both partners carry it, each pregnancy has a 1 in 4 chance of cystic fibrosis.
  • ACOG recommends offering CF carrier screening to everyone who is pregnant or planning a pregnancy.

What cystic fibrosis is

Cystic fibrosis (CF) is a recessive condition caused by changes in the CFTR gene. It makes mucus thick and sticky, which damages the lungs and digestive system. About 40,000 people in the US live with CF. New medicines called CFTR modulators have transformed care for many people, but it remains a serious, lifelong condition.

What being a carrier means

A carrier has one altered CFTR gene and one working copy. One working copy is enough, so carriers don't have CF and usually have no symptoms. Most find out only through screening, or after having an affected child.

Carrier odds by ancestry

AncestryChance of being a CF carrier
Ashkenazi Jewishabout 1 in 24
White (non-Hispanic)about 1 in 25
Hispanicabout 1 in 58
Black / African Americanabout 1 in 61
Asian Americanabout 1 in 94

For two white partners, the chance of a child with CF works out at about 1 in 2,500 per pregnancy. Try your own pairing in the carrier odds calculator.

If both partners are carriers

Each pregnancy has a 1 in 4 chance of CF, a 2 in 4 chance of a carrier child, and a 1 in 4 chance of neither. A genetic counselor explains the options: IVF with embryo testing, testing during pregnancy, or going ahead fully informed.

How CF carrier testing works

A blood or saliva test looks for changes in the CFTR gene. More than 2,000 changes are known, so tests look for the common ones or read the whole gene. Detection is highest in people of white and Ashkenazi Jewish ancestry and lower in others, so a negative result lowers your chance of being a carrier a lot, without making it zero. Expanded carrier screens include CF alongside hundreds of other conditions.

General information, not medical advice.

Sources

  1. ACOG Committee Opinion 691: Carrier screening for genetic conditions (2017)
  2. Gregg AR et al. Screening for autosomal recessive and X-linked conditions: ACMG practice resource. Genetics in Medicine (2021)
  3. Cystic Fibrosis Foundation
  4. MedlinePlus Genetics: What are the different ways a genetic condition can be inherited?

Two healthy people. One test.

The carrier check screens both of you for hundreds of recessive conditions at once, with a genetic counselor to explain the result as a couple.

Check our carriers

Questions people ask.

What does it mean to be a cystic fibrosis carrier?

A CF carrier has one altered CFTR gene and one working copy. Carriers don't have cystic fibrosis and usually have no symptoms, but they can pass the altered gene to their children.

How common are cystic fibrosis carriers?

About 1 in 25 white Americans and 1 in 24 Ashkenazi Jewish Americans carry a CF gene. Carrier rates are lower in Hispanic (about 1 in 58), Black (about 1 in 61) and Asian Americans (about 1 in 94).

What if both parents are CF carriers?

Each pregnancy has a 1 in 4 chance of a child with cystic fibrosis, a 2 in 4 chance of a carrier child, and a 1 in 4 chance of neither.

Should I get tested for cystic fibrosis carrier status?

ACOG recommends offering CF carrier screening to everyone who is pregnant or planning a pregnancy, regardless of ancestry.