Understand results guide

Carrier Status

Carrier status^* testing identifies people who carry one pathogenic variant for a recessive disease. Carriers are typically unaffected; the significance is reproductive. This guide covers interpreting carrier findings, when partner testing matters, and what patients need to understand.

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Orienting to the report

Each Carrier Status report covers a single condition. It names the gene and the select variants tested, since this is genotyping-based testing rather than full gene sequencing, and reports whether any of those variants were detected. Reports also include carrier detection rates for relevant ethnicities, which inform residual risk counseling.

Key framing for clinical use: For most patients, a carrier result has no effect on their personal health. Its significance is reproductive: for an autosomal recessive condition, when both partners carry a variant in the same gene, each pregnancy carries a 25% chance the child is affected.

**Carrier report** · Result overview: variants detected and the gene tested

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Result outcomes

What this means

Your patient carries one pathogenic variant for this condition. They are typically unaffected, but the finding can be important for family planning.

Next steps

If interested in family planning, offer comprehensive partner testing to determine overall risk to offspring.
If both partners are carriers, referral to genetic counseling is appropriate to discuss reproductive options.
Discuss the implications for biological relatives. Parents, siblings, and children of the patient are expected to have a 50% chance of also being a carrier.

How to talk to your patient: "Being a carrier doesn't usually affect your health. It means you carry one copy of this gene change. What matters for family planning is whether your partner carries a change in the same gene, and we can talk about whether that testing makes sense."

What this means

None of the variants screened for this condition were detected, however, this does not eliminate the risk of being a carrier. These reports only test select variants. Refer to the Scientific Details section of the report to review test coverage by ancestry.

Next steps

If the patient is interested in carrier screening for family planning, discuss the limitations of the test.
Per ACMG guidelines, offer universal pan-ethnic screening to all patients pregnant or planning a pregnancy, which goes beyond the genes and variants covered by 23andMe testing.

How to talk to your patient: “This test did not find the variants it screens for, which may lower the chance you are a carrier but does not rule it out. If you are thinking about having children, broader screening is available.”

What this means

Two pathogenic variants means the patient may be affected rather than a carrier. This is rare, and usually reflects an undiagnosed mild form of the disease or a variant combination producing a milder phenotype.

Next steps

With no known diagnosis, clinical evaluation and possible referral to a specialist is appropriate. Confirmatory testing should also be considered to guide medical management.
Refer to a genetic counselor if the patient is interested in family planning and understanding risk to family members.

How to talk to your patient: “This result points to something other than carrier status, so it is worth looking into further. It is not a diagnosis on its own. The next step is an evaluation and a clinical test to confirm what this means for you.”

What this means

The test could not generate a result for a variant or the full report. This usually reflects a sample quality or processing issue, not a positive or negative finding.

It can also reflect a test limitation: for certain variants the assay cannot tell whether a patient has two copies, so someone who is affected rather than a carrier may return this result. See the report's Indication for Use section for which variants this applies to.

Next steps

The patient may be eligible for a free replacement kit. Advise them to contact 23andMe customer support.
If a result is clinically time-sensitive, genetic testing through a CLIA-certified clinical laboratory is an appropriate alternative.

Carrier status reports. Gene, variant count, and the ancestry groups in which the tested variants are most common are listed for each.

Condition	Gene	Variants	Ethnicities in which the variants tested are most common
Agenesis of the Corpus Callosum with Peripheral Neuropathy	SLC12A6	1 variant	French Canadian
ARSACS	SACS	1 variant	French Canadian
Autosomal Recessive Polycystic Kidney Disease	PKHD1	3 variants	Not applicable
Beta Thalassemia and Related Hemoglobinopathies	HBB	10 variants	Cypriot, Greek, Italian, Sicilian, Sardinian
Bloom Syndrome	BLM	1 variant	Ashkenazi Jewish
Canavan Disease	ASPA	1 variant	Ashkenazi Jewish
Congenital Disorder of Glycosylation Type 1a (PMM2-CDG)	PMM2	2 variants	Danish
Cystic Fibrosis	CFTR	29 variants	European, Hispanic/Latino, Ashkenazi Jewish
D-Bifunctional Protein Deficiency	HSD17B4	2 variants	Not applicable
Dihydrolipoamide Dehydrogenase Deficiency	DLD	1 variant	Ashkenazi Jewish
Familial Dysautonomia	IKBKAP	1 variant	Ashkenazi Jewish
Familial Hyperinsulinism (ABCC8-Related)	ABCC8	3 variants	Ashkenazi Jewish
Familial Mediterranean Fever	MEFV	7 variants	Arab, Armenian, Sephardic Jewish, Turkish
Fanconi Anemia Group C	FANCC	3 variants	Ashkenazi Jewish
Gaucher Disease Type 1	GBA	3 variants	Ashkenazi Jewish
Glycogen Storage Disease Type Ia	G6PC	1 variant	Ashkenazi Jewish
Glycogen Storage Disease Type Ib	SLC37A4	2 variants	Not applicable
GRACILE Syndrome	BCS1L	1 variant	Finnish
Hereditary Fructose Intolerance	ALDOB	4 variants	European
Herlitz Junctional Epidermolysis Bullosa (LAMB3-Related)	LAMB3	3 variants	Not applicable
Leigh Syndrome, French Canadian Type	LRPPRC	1 variant	French Canadian
Limb-Girdle Muscular Dystrophy Type 2D	SGCA	1 variant	Finnish
Limb-Girdle Muscular Dystrophy Type 2E	SGCB	1 variant	Southern Indiana Amish
Limb-Girdle Muscular Dystrophy Type 2I	FKRP	1 variant	European
Maple Syrup Urine Disease Type 1B	BCKDHB	2 variants	Ashkenazi Jewish
MCAD Deficiency	ACADM	4 variants	Northern European
Mucolipidosis Type IV	MCOLN1	1 variant	Ashkenazi Jewish
Neuronal Ceroid Lipofuscinosis (CLN5-Related)	CLN5	1 variant	Finnish
Neuronal Ceroid Lipofuscinosis (PPT1-Related)	PPT1	3 variants	Finnish
Niemann-Pick Disease Type A	SMPD1	3 variants	Ashkenazi Jewish
Nijmegen Breakage Syndrome	NBN	1 variant	Eastern European
Nonsyndromic Hearing Loss and Deafness, DFNB1 (GJB2-Related)	GJB2	2 variants	Ashkenazi Jewish, European
Pendred Syndrome and DFNB4 Hearing Loss	SLC26A4	6 variants	Not applicable
Phenylketonuria and Related Disorders	PAH	23 variants	Northern European
Pompe Disease	GAA	5 variants	African/African American, European
Primary Hyperoxaluria Type 2	GRHPR	1 variant	European
Pyruvate Kinase Deficiency	PKLR	1 variant	Not applicable
Rhizomelic Chondrodysplasia Punctata Type 1	PEX7	1 variant	Not applicable
Salla Disease	SLC17A5	1 variant	Finnish, Swedish
Sickle Cell Anemia	HBB	1 variant	African
Sjögren-Larsson Syndrome	ALDH3A2	1 variant	Swedish
Tay-Sachs Disease	HEXA	4 variants	Ashkenazi Jewish, Cajun
Tyrosinemia Type I	FAH	4 variants	French Canadian, Finnish
Usher Syndrome Type 1F	PCDH15	1 variant	Ashkenazi Jewish
Usher Syndrome Type 3A	CLRN1	1 variant	Ashkenazi Jewish
Zellweger Syndrome Spectrum (PEX1-Related)	PEX1	1 variant	Not applicable

Detection rates vary by ancestry. A positive finding is clinically relevant regardless of a patient's ancestry. Ancestry affects how informative a negative result is: because the panel tests variants that are most common in the groups listed, a not-detected result rules out less for patients of other ancestries.

Condition spotlights

Clinical context for some of the autosomal recessive conditions covered by 23andMe.

Clinical resources

Sample reports, clinical downloads, educational videos, and external references all collected in one place.

Go to Resources →

Questions about a specific result? Contact our clinical team at medical@23andme.com

Frequently asked questions

A carrier is a person who has one copy of a variant in a gene associated with a recessive genetic condition. In most cases, carriers do not have the condition themselves. Two copies of the variant (one from each parent) are typically required for the condition to be expressed. Carriers can, however, pass the variant to their children. If both parents are carriers of the same condition, each pregnancy carries a 25% chance of the child inheriting two copies of the variant and being affected.

Carriers are generally healthy individuals with no prior reason to suspect their carrier status. Identifying this risk, particularly before a pregnancy, gives individuals and couples the opportunity to make informed reproductive decisions, including whether to pursue partner testing, prenatal diagnosis, or other family planning considerations.

A carrier result is informative for reproductive planning, not an indicator of personal health risk. The key counseling message is that carrier status alone typically does not cause the condition or require medical management. The most important next step is offering partner testing. If the partner tests negative for variants in the same gene, the risk of having an affected child is low, though not zero depending on the variants tested. If the partner is also a carrier of the same condition, referral to genetic counseling is recommended to discuss reproductive options.

Ideally, carrier testing and partner follow-up occur before conception so couples have the full range of reproductive options available. If a patient is already pregnant, time-sensitive options such as prenatal diagnostic testing may still be available.

Yes. The American College of Medical Genetics and Genomics (ACMG) recommends expanded carrier screening for individuals planning a pregnancy or in early pregnancy, ideally before conception. 23andMe's carrier screening covers select variants across more than 40 conditions, but it is not equivalent to a comprehensive clinical carrier screening panel. For patients planning a pregnancy, referral for clinical carrier screening through their OB/GYN or a genetic counselor is appropriate regardless of their 23andMe result.

Additional carrier screening may also be warranted based on a patient's personal or family history. A genetic counselor can help determine whether condition-specific or more targeted testing is appropriate for their situation.

Yes. A “not detected” result does not rule out carrier status. 23andMe's carrier reports cover the most common variants for each condition but do not sequence the entire gene. For a patient with a strong family history, more comprehensive clinical genetic testing may be appropriate regardless of the 23andMe result. A genetic counselor can help determine the most appropriate testing strategy and interpret results in the context of family history.

Important test information

* Genetic Health Risk, Carrier Status & PRS reports: The 23andMe PGS test includes health predisposition and carrier status reports. Health predisposition reports include both reports that meet FDA requirements for genetic health risks and PRS reports which are based on a genetic model that includes data and insights from 23andMe consented research participants, and have not been reviewed by the FDA. The test uses qualitative genotyping to detect select clinically relevant variants in the genomic DNA of adults from saliva for the purpose of reporting and interpreting genetic health risks and reporting carrier status. It is not intended to diagnose any disease. Your ethnicity may affect the relevance of each report and how your genetic health risk results are interpreted. Each genetic health risk report describes if a person has variants associated with a higher risk of developing a disease, but does not describe a person’s overall risk of developing the disease. Each PRS report describes if a person has a certain likelihood of developing a condition, but does not describe a person’s overall likelihood. The test is not intended to tell you anything about your current state of health, or to be used to make medical decisions, including whether or not you should take a medication, how much of a medication you should take, or determine any treatment. Our carrier status reports can be used to determine carrier status, but cannot determine if you have two copies of any genetic variant. These carrier reports are not intended to tell you anything about your risk for developing a disease in the future, the health of your fetus, or your newborn child's risk of developing a particular disease later in life. For certain conditions, we provide a single report that includes information on both carrier status and genetic health risk. Warnings & Limitations: The 23andMe PGS Genetic Health Risk Report for BRCA1/BRCA2 (Selected Variants) is indicated for reporting of 44 variants in the BRCA1 and BRCA2 genes. The report describes if a person's genetic result is associated with an increased risk of developing breast cancer and ovarian cancer and may be associated with an increased risk for prostate cancer, pancreatic cancer, and potentially other cancers. The variants included in this report do not represent the majority of the BRCA1/BRCA2 variants in people of most ethnicities. This report does not include variants in other genes linked to hereditary cancers and the absence of variants included in this report does not rule out the presence of other genetic variants that may impact cancer risk. This report is for over-the-counter use by adults over the age of 18, and provides genetic information to inform discussions with a healthcare professional. The PGS test is not a substitute for visits to a healthcare professional for recommended screenings or appropriate follow-up. Results should be confirmed in a clinical setting before taking any medical action. For important information and limitations regarding each genetic health risk and carrier status report, visit 23andme.org/shop/test-info/

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Cystic Fibrosis (CFTR)

Sickle Cell Anemia (HBB, HbS)

Tay-Sachs Disease (HEXA)

Clinical resources