The Importance of Reproductive Carrier Screening

 

Cystic fibrosis, spinal muscular atrophy, and fragile X syndrome, three of the most common familial disorders, affect 1 in 1500 babies1; this is the equivalent to the combined risk of trisomy 18, trisomy 13, and Turner syndrome. Many people have no family history and are unaware they are carriers.

Cystic Fibrosis1 1 in
3,000 births
Spinal Muscular Atrophy1 1 in 6,000 –
10,000 births
Fragile X Syndrome1 1 in 7,000 –
11,000 births
Carrier Status Carrier Status

A carrier is a person who has a genetic change, or mutation, in their DNA, but in most cases does not have any associated health problems.

 

People who are both carriers for the same disorder have a 25% (or 1 in 4) chance of
having a child that will be affected by that disorder.

The American College of Obstetricians and Gynecologists (ACOG) recommends that information about reproductive carrier screening be offered to everyone either prior to conception (preferred) or in early pregnancy.2

The Sonic Difference

 

End-to-end laboratory partner

Seamless and non-disruptive integration with office workflows

NIPT ICON2

Extensive interface experience

EHR interfaced results delivered securely in an optimized report format

NIPT ICON3

Conclusive and patient-friendly results

Available through our online patient portal, SonicMyAccess

NIPT ICON4

Best-in-class access

Local pathology support and access to over 500 patient service centers in the U.S.

NIPT ICON5

Genetic counseling 

Post-test sessions with licensed and board-certified genetic counselors

NIPT ICON4

Billing services and price estimates

Dedicated care specialist team for patient eligibility, benefits verification, and prior authorization services

 

Advanced technology and unparalleled support

 

Carrier screening identifies patients who are at increased risk of having a child affected with a genetic disorder, providing actionable information for the next steps of their reproductive journey. Our Medical leaders and scientific experts have selected the mutations most relevant to genetic carrier conditions and use cutting-edge technology for the most optimal detection rates.

 

Condition

Genes

Risk

Cystic fibrosis (CF) affects respiratory and gastrointestinal function, resulting in progressive lung disease, recurrent respiratory tract infection, pancreatic insufficiency, and male infertility. Common mutations in the CFTR gene, responsible for >85% of cases of CF. A couple can have a child with CF if they are both carriers. When both partners are carriers, they have a 25% risk of having an affected child.
Spinal muscular atrophy (SMA) is characterized by progressive symmetric muscle weakness and atrophy that can be complicated by respiratory, orthopedic and nutritional comorbidities. Deletions of the SMN1 gene, responsible for 96% of cases of SMA. A couple can have a child with SMA if they are both carriers. When both partners are carriers, they have a 25% risk of having an affected child.
Fragile X syndrome (FX) is the most common form of inherited intellectual disability, developmental delay and behavioral abnormalities, including autism. Expansions of the CGG triplet repeat region of the FMR1 gene, responsible for 99% of cases of FX. Female carriers are at 50% risk of passing the expansion to their children. The risk of having a child with FX depends on the size of the expansion and the sex of the child (males being more severely affected).

Male and female carriers of premutations are at increased risk of tremor/ataxia syndrome and premature ovarian insufficiency (women).

Increased carrier status detection rates for a broad range of inherited conditions  

 

Sonic offers upgraded universal carrier screening panels. These panels feature next-generation sequencing coverage of 99% of bases at >20x and copy number variant (CNV) analysis for all genes which includes specific recurrent CNVs.3

 

Ashkenazi Jewish Panel

Screening for individuals of Ashkenazi Jewish descent

Classic Panel

Screens for conditions based on recommendations from ACOG and ACMG*

Basic Panel

The most commonly requested tests

Complete Panel

The most comprehensive screening

* American College of Medical Genetics and Genomic

Genetic Carrier Screening Test Menu

Individual Conditions 

 

  Cystic Fibrosis 39

  Cystic Fibrosis 139

  Hemoglobinopathy/Thalassemia

  Spinal Muscular Atrophy (SMA)

  Fragile X Screen w/ Reflex Methylation

Carrier Screening 

 

  Ashkenazi Jewish Panel, Female (39 genes)

  Ashkenazi Jewish Panel, Male (37 genes)

  Basic Duo, Female & Male (CF, SMA)

  Basic Trio, Female (CF, SMA, FX)

  Basic Plus Hemoglobinopathies, Female

  Basic Plus Hemoglobinopathies, Male

  Classic Panel, Female (24 genes)

  Classic Panel, Male (22 genes)

  Complete Panel, Female (157 genes)

  Complete Panel, Male (147 genes)

 

* Note that carrier testing of males for FX is not ordered routinely as part of the reproductive carrier screen. If clinically indicated, on the basis of family history or clinical features, FX may be appropriate. Due to the predictive nature of this testing, genetic counseling is strongly recommended.

 

Testing Procedure

 

The best time to establish carrier status is prior to conception. However, carrier screening may be performed any time during pregnancy but is recommended as early in pregnancy as possible. 
 

4 Step Testing Process

 

Testing can be performed on individuals or couples. There are two options for 
carrier testing:

 

Group 2453
A sample is collected and tested from the pregnant partner first. If found to be a carrier, a sample can be collected from the other partner for carrier screening for the same disorder.
Group 2452
Samples are collected from both partners and tested simultaneously. In the event of a positive screen, anxiety while waiting for the second result can be avoided.

References:

1. Data from: www.cff.org | www.fragilex.org | www.ama-assn.org
2. Carrier Screening for Genetic Conditions. Committee Opinion No.691. American College of Obstetricians and Gynecologists. Obstet Gynecol 2017.
3. www.baylorgenetics.com/news/test-update-geneaware/

Important Test Information:

It is important to note that no preconception carrier screen is able to detect every mutation that might cause a genetic condition. The test does not detect every mutation that can cause cystic fibrosis, spinal muscular atrophy, and fragile X syndrome, or mutations in other genes responsible for other disorders. If no mutation is found, the risk of the patient being a carrier for these conditions is greatly reduced, however the possibility cannot be eliminated. The patient’s ethnicity may also affect carrier risk.