Carrier screening

Carrier screening identifies individuals who carry a pathogenic/likely pathogenic variant for an autosomal recessive or X-linked condition. Carriers are typically unaffected but may have an increased chance of having an affected child.

Consistent with ACOG guidance, carrier screening should be offered to all individuals who are pregnant or planning pregnancy, regardless of race, ethnicity, or family history. This approach supports equitable access to testing and avoids reliance on ancestry-based risk assessment.

The American College of Medical Genetics (ACMG) also recommends offering carrier screening to all patients who are pregnant or planning pregnancy and emphasizes an ethnic/population-neutral approach to promote equity and inclusion). ^{¹ ²}

Carrier screening is ideally performed before pregnancy, when patients have the greatest range of reproductive options. However, screening during pregnancy is appropriate and commonly performed, particularly when preconception testing was not completed. ¹

Carrier screening is available in variable panel sizes, allowing flexibility based on patient preferences and clinical context:

- Targeted panels focus on a small number of common or guideline-recommended conditions.

- Expanded panels assess dozens to hundreds of genes associated with serious inherited childhood conditions.

Larger panels increase the likelihood of identifying carrier status, while smaller panels may be appropriate for patients who prefer a more limited scope of testing. ACOG supports the use of expanded carrier screening and notes that it can simplify testing by removing the need for ancestry-based panel selection. ¹

Further, ACMG explicitly recommends that carrier screening paradigms be ethnic and population neutral to improve equity and avoid scientific limitations of self-reported ethnicity. ²

See the Helix test menu for detailed information on available panels and genes included on each.

Helix carrier screening is performed using a saliva specimen. The option of submitting a blood specimen will be coming soon.

Results are returned within 2-3 weeks, with an average under 2 weeks.

Helix offers multiple payment options, including insurance billing, cash-pay, and in some cases, billing to your clinic. To learn more, please visit helix.com/billing.

The core method is Next-Generation Sequencing (NGS), which provides full gene sequencing of the coding regions. Copy number variants are detected using a proprietary bioinformatic algorithm. Repeat-primed PCR (rpPCR) is also added for FMR1 to detect CGG repeat expansions associated with Fragile X syndrome.

> 98% detection rate across all genes. All results are confirmed before reporting.

Male patients will not be screened for X-linked conditions. If an X-linked condition is suspected in a male patient, please contact Helix about diagnostic testing for that specific disorder.

Common result types include:

- Negative: No pathogenic variants identified in the genes tested.

- Carrier (Positive): One pathogenic variant identified in an autosomal recessive gene or a pathogenic variant in an X-linked gene.

Yes. Pathogenic variants found by NGS or the CNVexon™ algorithm are confirmed using orthogonal methods like Sanger sequencing, MLPA (such as for SMN1), or quantitative PCR (qPCR).

No, Helix does not report variants of uncertain significance on our carrier screening tests. Only variants classified as "Pathogenic" or "Likely Pathogenic" are reported, following ACMG guidelines for sequence variant interpretation. An in-house algorithm is used to calculate residual risk. If detailed information on variants of uncertain significance for a specific gene is required, diagnostic testing is recommended.

If a patient is a carrier, partner testing is recommended for the same gene. If both partners are carriers of the same autosomal recessive condition—or if the patient is a carrier of an X-linked condition—genetic counseling is recommended to review reproductive risks and options. ¹

When both partners are carriers of the same autosomal recessive condition, there is a 25% chance with each pregnancy to have an affected child. Genetic counseling can support discussion of reproductive options, including prenatal testing, IVF with PGT-M, or other pregnancy planning considerations. Post-test genetic counseling is available for no additional charge through Helix.

No. A negative result reduces—but does not eliminate—the chance of being a carrier. Residual risk depends on the genes tested, detection rates, and the patient’s background.

Helix has a pre-test patient education video as well as a carrier screening patient brochure. Helix also offers post-test genetic counseling for any patient with a positive carrier screen.

Pre-test genetic counseling is not required to order carrier screening. However, genetic counseling is strongly recommended for:

• Positive carrier results
• Carrier couples
• X-linked findings
• Complex or time-sensitive scenarios
  

Carrier screening is a genetic test. Genetic tests examine parts of your DNA called genes. Genes determine traits, such as eye color, hair color and blood type, and are inherited from our parents. Variation in genes may also influence your child’s risk of developing certain diseases. Carrier screening can help you and your partner learn if you carry gene changes that could affect your future child’s health. Many people choose this testing to feel informed and prepared, and most results offer reassurance rather than concern. Carrier screening offers a way to learn more about your growing family and support the healthiest possible start for your baby.

Professional medical organizations recommend offering carrier testing to all pregnant patients and to those planning a pregnancy. You do not need a family history of a genetic condition to have carrier screening. A person can be a carrier of a genetic disease and not have any signs of it in their personal or family history. We all carry changes in our genes—most do not affect us. However, if one or both parents carry a gene change linked to a particular genetic condition, it can cause a child to be born with that condition.

The conditions included on a carrier screen are generally serious health conditions that can affect a child’s growth, development, or life expectancy. Some of these conditions are treatable with medications and therapies, while others do not have effective treatment options and can be life-limiting. Carrier screening gives families the chance to learn about these risks in advance and make informed choices.

Many people first learn about carrier screening during pregnancy, and doing the test during pregnancy can provide valuable information to help guide your care and learn more about your baby’s health. If carrier screening is performed before pregnancy, it gives you the most options and time to plan.

Helix carrier testing is performed on a saliva sample to look for genetic changes in the parents. Results are returned within 2-3 weeks, with an average under 2 weeks.

Carrier screening comes in different sizes:

• Smaller panels test for a few common conditions.
• Expanded panels test for many conditions at the same time.

Your healthcare provider can help you decide which option is right for you.

If your Helix carrier screening result is negative, your chance of passing on one of the conditions is much lower, though not zero.

If you have a positive carrier screening result, it does not mean you have the condition. Your healthcare provider may recommend screening your partner for the same condition. If your partner is also a carrier for that same condition, there’s a 1-in-4 or 25% chance that a child could be affected.

If you are a carrier for a condition on the X chromosome, your partner will not need to be tested to determine risk. Your healthcare provider or genetic counselor will explain the specific risks for your children.

If you and your partner both carry the same condition or you carry a condition on the X chromosome, your healthcare provider or a genetic counselor can help you understand what that means and what your options are. During pregnancy, you might choose diagnostic testing, such as chorionic villus sampling or amniocentesis to determine if the pregnancy is affected by the condition. For future pregnancies, options like In-Vitro-Fertilization with preimplantation genetic testing, donor eggs or sperm, or adoption may be considered.

If both partners are carriers of the same condition, there may be a higher chance for a child to be affected. In this case, you may be offered genetic counseling to talk through results, risks, and options.

A negative result lowers the chance that you are a carrier, but it cannot remove all risk. No genetic test can test for every possible condition.

Your healthcare provider can review your results with you. Genetic counseling may be available to you through your healthcare institution. If not, Helix offers genetic counseling for patients with a positive carrier screening result. Your healthcare provider can help you schedule genetic counseling.

No. A negative result reduces—but does not eliminate—the chance of being a carrier. Residual risk depends on the genes tested, detection rates, and the patient’s background.