NTSAD International Tay-Sachs Carrier
Testing Quality Control Program

The NTSAD International Tay-Sachs Carrier Testing Quality Control Program is a voluntary laboratory proficiency testing program. The program evaluates laboratory performance of Hex A enzyme testing, in serum and leukocytes. While testing may be performed on either serum or leukocytes for most individuals, leukocyte testing is more accurate for individuals taking insulin and women who are pregnant or on birth control pills.

Results from carrier testing by enzyme analysis will determine that an individual has enzyme levels that are consistent with being either a non-carrier, or a carrier, or are indeterminate. An indeterminate result falls between the carrier and non-carrier ranges. Individuals with carrier or indeterminate enzyme results should have carrier testing by DNA analysis. DNA mutation analysis tests for a subset of the over 100 Tay-Sachs mutations and may provide important information for genetic counseling. DNA mutation analysis, which will detect approximately 94% of Ashkenazi Jewish carriers and a lower percentage of non-Jewish carriers, may help clarify whether an individual carries a mutation associated with infantile Tay-Sachs, Late Onset Tay-Sachs or is a carrier of a pseudodeficiency allele. Approximately 30% of non-Ashkenazi Jewish, and 3% of Ashkenazi Jewish individuals who are identified as carriers by enzyme analysis are carriers of a benign pseudodeficiency allele and not at increased risk to have a child with Tay-Sachs disease.

Please note: these are the medical labs participating in the NTSAD International Laboratory Quality Control Carrier Testing Tay-Sachs Program. It does not include collection centers, which send samples to others labs for processing. For information on collection centers in your area please contact the national office: 800.906.8723 or Info@ntsad.org.

The Quality Control Program’s goal is to assist labs in reaching and maintaining proficiency in Tay-Sachs enzyme assay carrier testing. The program, which was founded and administered by Dr. Mike Kaback at the University of California-San Diego for 25 years, has recently been transferred to the lab of nationally acclaimed researcher Dr. Mimi Blitzer at the University of Maryland.