Carrier Screening From Your DNA Data: A Guide for Family Planning

A carrier is someone who has one working copy and one non-working copy of a gene for a recessive genetic condition. Carriers are typically healthy — one working copy is enough to produce sufficient protein. But if both parents are carriers of the same condition, each pregnancy has a 25% chance of the child being affected.

Carrier screening identifies whether you carry variants associated with recessive genetic conditions like cystic fibrosis, sickle cell disease, Tay-Sachs disease, and many others.

Clinical carrier screening panels cost $250–$2,000+ per person out of pocket. If you've already taken 23andMe or AncestryDNA, your raw data contains many of the same variants that clinical panels test for — you've already paid for the genotyping.

GenomeInsight screens your existing raw data for carrier variants in 15+ conditions including:

• Cystic Fibrosis (CFTR) • Sickle Cell Disease (HBB) • Tay-Sachs Disease (HEXA) • Phenylketonuria (PAH) • Spinal Muscular Atrophy (SMN1) • Beta-Thalassemia (HBB) • Gaucher Disease (GBA) • Hereditary Hemochromatosis (HFE) • Alpha-1 Antitrypsin Deficiency (SERPINA1) • And more...

Consumer DNA arrays test specific SNP positions — they don't sequence entire genes. This means:

1. Not all pathogenic variants are tested. Cystic fibrosis has over 2,000 known mutations. Consumer arrays typically test for ΔF508 (the most common, accounting for ~70% of CF alleles in European populations) and a handful of others.

2. A negative result doesn't guarantee you're not a carrier. It means the specific variants tested weren't detected. Residual carrier risk depends on your ethnicity and the variants covered.

3. Some conditions require copy number analysis. Spinal Muscular Atrophy (SMA) carrier testing typically requires a separate assay not available on consumer arrays.

If you're planning a family and carrier status results concern you, follow up with clinical-grade carrier screening through a genetic counselor.

GenomeInsight shows three possible results for each condition:

✅ Not a Carrier — The tested variants were not detected. Your residual risk is low (but not zero — see limitations).

⚠️ Carrier — You carry one copy of a pathogenic variant. You are likely healthy but could pass the variant to children. Partner screening is recommended.

🔴 Affected/Homozygous — You carry two copies. This may indicate you are affected by the condition. Clinical confirmation is strongly recommended.

The most important action: if you are identified as a carrier, your partner should also be screened. If both partners carry the same condition, genetic counseling before pregnancy can outline all available options.

Carrier frequencies vary dramatically by ethnic background:

• Cystic Fibrosis: 1 in 25 Northern Europeans, 1 in 65 African Americans, 1 in 90 Asian Americans • Sickle Cell Disease: 1 in 12 African Americans, 1 in 100 Hispanic Americans, rare in Europeans • Tay-Sachs: 1 in 30 Ashkenazi Jewish, 1 in 300 general population • Beta-Thalassemia: 1 in 25 Mediterranean/South Asian, 1 in 50 Southeast Asian • Hereditary Hemochromatosis: 1 in 10 Northern Europeans (C282Y carriers)

GenomeInsight's ancestry analysis helps contextualize your carrier results within your ethnic background.