Expanded Carrier Screen (281 Genes)

Related Gene(s): Please download the brochure for a full list of genes screened for.

Sema4 Expanded Carrier Screen (ECS) is one of the most comprehensive carrier screens available. It screens for inherited disorders associated with 281 genes, including many conditions that are prevalent in people of certain ethnic backgrounds. For example, Sema4 ECS includes a Comprehensive Jewish Carrier Screen for 96 genes.

Six testing technologies are used in parallel to ensure the highest detection rate for each gene based on gene-specific mutation mechanism. A blood sample is drawn and DNA is obtained from the white blood cells. High-throughput, next generation sequencing is performed to examine multiple genes at one time. In addition, some of the genes on the panel may be partially subjected to Sanger sequencing due to inadequate sequence coverage by next generation sequencing and targeted pathogenic variants may be analyzed by allele specific primer extension analyses. Certain genes that are not amenable to sequencing undergo Targeted Mutation Analysis to look for the presence of specific pathogenic variants. Fragile X CGG repeats analysis is performed by PCR amplification followed by capillary electrophoresis for allele sizing. Samples positive for FMR1 CGG repeats in the premutation or full mutation size ranges are further evaluated by Southern blot analysis. Multiplex Ligation-Dependent Probe Amplification (MLPA) is used to detect copy number changes for spinal muscular atrophy, alpha thalassemia, and Duchenne/Becker muscular dystrophies.

All testing is approximately 99% accurate. A negative test result for any given disease does not exclude an individual from being a carrier for that disease, but only reduces the risk of being a carrier. The patient may still have a pathogenic variant that was not identified by this testing. Please refer to the residual risk tables found in the Sema4 Expanded Carrier Screen brochure to determine the risk following a negative result.

With Sema4 ECS, carrier screening may be easily customized to address specific clinical needs. Testing can be performed for all 281 genes, a smaller subset of genes, or even just one gene. To learn more, explore the full list of diseases that this test screens for.

For prenatal samples, please contact our laboratory at 212-241-7518 for more information.

Specimen Requirements

  • Blood: One 5-10 mL tube with ACD (yellow top) and two 5-10 mL tubes with EDTA (lavender top)
  • We accept saliva specimens to perform follow-up molecular testing for partners of identified carriers. Please contact our laboratory to obtain saliva kits

Ordering Information


  • Ship at room temperature

Turnaround Time

  • 7-14 days


Carrier Screening Requisition
Expanded Carrier Screen Brochure