Clinical Services

Enhanced Genetic Screening (EGS) Program

30 years ago, 90% of the time we performed CVS or amniocentesis to test for a Mendelian disorder (such as cystic fibrosis, sickle cell, Spinal Muscular Atrophy, or Tay Sachs), it was because the couple already had an affected child. Now about 95% of the time we can determine if they are at high risk BEFORE they have an affected child.

It is well-known that certain inherited disorders are more common in some ethnic/racial groups. However, the total number of affected individuals is usually higher in the “low risk” group than high risk groups because there are so many more people who are considered low risk but are still carriers. Examples of ethnic group risks include sickle cell for African patients, Tay Sachs for Ashkenazi Jewish patients, and β-thalassemia for Mediterranean patients. Today, the best approach is to run a large panel with hundreds of disorders tested rather than rely upon family histories of their background which are commonly inaccurate. For most patients the incidence of having a baby with one of these types of disorders is actually more common than Down syndrome.

Lab panels are constantly evolving both in number of disorders, the methodology used by the lab, and the statistical performance (i.e., how accurate is the test for each disorder). Most of the tests we run have panels of over 500 Mendelian disorders.

Screening

Enhanced genetic screening (EGS) program includes:

• At the basic end of the spectrum, offering first trimester chromosomal risk evaluation either by cell free fetal DNA screening (NIPT) and Nuchal Translucency (NT) screening.
• Older, cheaper, but less effective biochemical screening with free β hCG and PAPP-A screening, is also available.
• As NIPT detects only a small percentage of anomalies as compared to diagnostic testing and advanced molecular laboratory, we bypass the NIPT for patients having diagnostic testing.
• Current approaches: Offering pan ethnic comprehensive screening for Mendelian disorders for hundreds of disorders including cystic fibrosis, Tay Sachs, the Ashkenazi panel, Fragile X, spinal muscular atrophy, and hundreds of other disorders that can have serious to lethal consequences for an affected individual.
• Genetic counseling- to review and explain all the above to couples so they can make whatever decisions they feel are appropriate for them.